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Investigations on the Desmid Biodiversity of Certain Regions of Eastern Himalayas Thesis submitted to The University of Burdwan For the Degree of DOCTOR OF PHILOSOPHY IN BOTANY By DEBJYOTI DAS Department of Botany, The University of Burdwan Burdwan 713104, West Bengal, India 2013

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Page 1: Investigations on the Desmid Biodiversity of Certain ...shodhganga.inflibnet.ac.in/bitstream/10603/21604/1/debjyoti das, ph.d. thesis.pdf(0342) Gram Date: 14/03/2013 Certified that

Investigations on the Desmid

Biodiversity of Certain Regions

of Eastern Himalayas

Thesis submitted to The University of Burdwan

For the Degree of

DOCTOR OF PHILOSOPHY IN BOTANY

By

DEBJYOTI DAS

Department of Botany, The University of Burdwan

Burdwan – 713104, West Bengal, India

2013

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Dedicated to

my beloved

teacher

Golam Mustafa

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Date: 14/03/2013

Certified that Mr. Debjyoti Das has carried out the investigation

incorporated in the thesis entitled “Investigations on the Desmid

Biodiversity of certain regions of Eastern Himalayas” under my

supervision and guidance. He has fulfilled the requirements as per

regulation of the University of Burdwan. The thesis which embodied

the results of his original investigations is submitted in partial

fulfillment of the degree of Doctor of Philosophy in Science of the

University of Burdwan.

As far as I know, the results incorporated in the present thesis have

not been submitted for any other degree or diploma elsewhere.

(JAI PRAKASH KESHRI)

Dr. Jai Prakash Keshri

Associate Professor in Botany

Department of Botany

The University of Burdwan Burdwan 713104

West Bengal, India Phone : (0342)2556549 (EPBX) Extn. 418

(0342)2656427 Direct (0342) 2659087 (R)

Fax : 91-0342-2656427

Gram : BURDSITY

e-mail [email protected]

[email protected]

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DECLARATION

I hereby declare that the thesis entitled “Investigations on the

Desmid Biodiversity of certain regions of Eastern Himalayas”

submitted for the Ph.D. degree has not been previously submitted by

me for any degree or diploma of any other University.

PLACE:

DATE:

(DEBJYOTI DAS)

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ACKNOWLEDGEMENTS

I hereby express my deep sense of gratitude and respect to my supervisor & guide Dr.

Jai Prakash Keshri, Associate Professor in Botany, CAS in Botany, The University of

Burdwan for his kind supervision throughout the entire period of project work.

I am also grateful to Late Golam Mustafa and Mr. Akshoy Kr. Chakrabarty, teachers

of Phycology Laboratory of this department for their various help and suggestions.

I acknowledge University Grants Commission (UGC), New Delhi, for financial

assistance.

I express my deep sense of gratitude to Home Department, Government of Sikkim,

for necessary permission for exploration to some of the restricted localities and help

extended.

My sincere thanks are due to the Forest Department and Secretariat, Government of

Sikkim, for necessary permission to visit the areas under their control.

I am grateful to Head of the Department, CAS in Botany, The University of Burdwan

for providing laboratory facilities.

I would like to express sincere regard to all the teachers of this department for their

valuable suggestions.

I am thankful to Dr. Gautam Ganguly for his help and suggestions related to field

collection.

I am extremely thankful to Baisakhi Mukherjee, Banasri Mahata, Subhabrata Ghosh,

Surajit Roy, Jayanta Sikdar, Shilpa Datta and Mousumi Das, research scholars of the

Phycology section of this department for their cooperation and support in various

ways.

I am also grateful to all the staffs and non-teaching members specially Mr. Kaushik

Sarkar, of this department for various help.

I am also indebted all other scholars of this department for their support.

I express my appreciation to authority of Botanical Survey of India (BSI), especially

to Dr. R.K. Gupta, Scientists, BSI, for providing necessary permission for library

access.

I am extremely thankful to all my friends to conspire and enhance my confidence.

Finally I convey my deep sense of admire and regards to my parents and family

members for their endurance and encouragement during this research work.

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CONTENTS

SUMMARY i-ii

INTRODUCTION 1-6

REVIEW OF LITERATURE 7-28

MATERIAL AND METHODS 29-37

ECOLOGY 38-39

STSTEMATIC PART 40-222

GENERAL DISCUSSION AND CONCLUSION 223-231

LITERATURE CITED 232-249

FIGURES PLATE 1-30

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ABBREVIATIONS USED

B : Breadth

C : Celsius

cc. : Cubic Centimeter

f. : Figure/Figures

ft : Feet

F : Fahrenheit

gms. : Grams

km : Kilometer

L : Length

ml : Milliliter

No. : Number

pH : Hydrogen Ion Concentrations

Pl. : Plate

temp. : Temperature

µm : Micrometer

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i

SUMMARY

In the present systematic study certain regions of Eastern Himalaya including most

part of Sikkim and northern region of West Bengal (Kalimpong, Lava, Lolegaon etc.)

were selected. Total 1000 algal samples were collected from almost all accessible

localities and habitats from these regions. pH, temperature and brief ecological notes

were taken in the collection spots. All the collections were preserved in FAA solution

in amber coloured bottles and stored in the algal herbarium in the Phycology sections,

The University of Burdwan. Water samples were preserved in Lugols’ iodine solution

in the ratio of 100:1 for planktonic desmids. Algal samples were observed under

compound microscope and camera-lucida drawings were made. Photomicrographs of

desmids were also taken. Total 272 taxa under 27 genera of desmid have been

identified using standard monographs and available literature. Out of 272 taxa 25

members under 7 genera include Saccoderm desmids and 247 members under 20

genera belonging to Placoderms. 24 taxa under 3 genera (Actinotaenium, Closterium

& Cosmarium) have been described as new to science. In addition one new

combination under Cosmarium [C. cohnii (Nobilis) Keshri et Das] has also been

proposed. A list of new taxa is appended. 6 genera (Ancylonema, Roya, Spirotaenia,

Teilingia, Triplastrum and Triploceras) are new addition to the desmid flora of

Eastern Himalaya. 86 taxa under 18 genera are new addition to Indian desmid flora,

and 172 taxa are new addition to Eastern Himalayan desmid flora. Several lakes and

stagnant water bodies has been found better availability for desmid vegetation. They

have been found to grow in association with mosses and other angiospermic weeds of

which water pH was found little acidic. From altitude of above 17,000 ft several

desmid taxa have also been reported.

Following are the names of taxa proposed as new to science:

1. Actinotaenium sikkimicum sp. nov.

2. Closterium bitangchoianum sp. nov.

3. Closterium mamenchoeanum sp. nov.

4. Closterium pseudocynthia sp. nov.

5. Closterium pseudoincurvum sp. nov.

6. Closterium reticulatum sp. nov.

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7. Closterium sikkimicum sp. nov.

8. Cosmarium pseudocyclicum sp. nov.

9. Cosmarium pseudodebaryi sp. nov.

10. Cosmarium pseudolundellii sp. nov.

11. Cosmarium pseudoobsoletum sp. nov.

12. Cosmarium sikkimicum sp. nov.

13. Cosmarium subphaseolanum sp. nov.

14. Cosmarium yoksomum sp. nov.

15. Closterium arcuarium Hughes var. sikkimense var. nov.

16. Closterium libellula Focke ex Nordstedt var. sikkimense var. nov.

17. Closterium littorale Gay var. indicum var. nov.

18. Closterium minutum Roll var. indicum var. nov.

19. Closterium rostratum Ehrenberg ex Ralfs var. sikkimicum var. nov.

20. Cosmarium favum West et GS West var. indicum var. nov.

21. Cosmarium longicylindricum Scott et Grönblad var. indicum var. nov.

22. Cosmarium ornatum Ralfs var. sikkimicum var. nov.

23. Cosmarium pyramidatum Brébisson ex Ralfs var. indicum var. nov.

24. Cosmarium undulatum Corda ex Ralfs var. indicum var. nov.

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Introduction

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INTRODUCTION

1

INTRODUCTION

What are desmids & Why desmids?

Desmids are the minute, microscopic, unicellular, freshwater algae belonging to the

class Chlorophyceae and are the most interesting creature of the level of primary

producers. They have been paid little attention on its role as pollution indicators

(Brook 1981). Their occurrence may vary depends upon the chemistry of water body.

Thus they can be considered useful in typification of water bodies.

Majority of desmids composed of two halves called semicells, which are joined in the

isthmus region forming sinus. Each semicells have one or more chloroplasts with one

or several prenoids. Desmids are strictly fresh water algae. Their preferred occurrence

is on stagnant water bodies of lakes. Small water bodies separated by stones adjacent

to streams (pokhri, khola), reservoir, bog pools, in association of moss vegetation

attached on rock or bark of trees etc are very good habitats for their occurrence.

Sphagnum bogs and aquatic weeds in acidic habitats are definite spots of the

External and internal

morphology of a typical

desmid (Cosmarium sp.)

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INTRODUCTION

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occurrence of desmids. It has been observed that desmids prefer little acidic

environment for their growth.

Systematic position of desmids:

Systematically desmid members are very difficult to classify. Several desmidologists

categorized this group in various ways. The classification of desmids has been

changed from time to time. Brook (1981) has given the following outline of

classification that has been followed in this study.

Class: Chlorophyceae

Order: Zygnematales

Family I. Mesotaeniaceae

Order: Desmidiales

Family I. Gonatozygaceae

II. Peniaceae

III. Closteriaceae

IV. Desmidiaceae

The Study area:

Eastern Himalaya is the region encompassing Bhutan, north-eastern India (Sikkim,

Assam, Arunachal Pradesh, Meghalaya, Darjeeling districts of West Bengal etc.), and

southern, central, and eastern Nepal. The region is geologically young and has a more

complex geographical as well as floristic composition and shows high altitudinal

variations. This research work was carried out covering most part of Sikkim and few

regions of Darjeeling district of West Bengal (Kalimpong, Lava, Lolegaon etc.).

Sikkim ("Goodly Region" in Devanagari, or Shikim, Shikimpati or Sikkim; Lepcha:

Mayel Lyang; Limbu: Yuksom, "one of the fortified place") is a landlocked Indian

state nestled in the Eastern Himalayan mountains, spread the Mount

Khanchendzonga, (28,209 ft.), the third highest Mountain in the world. The state

borders Nepal to the west, China's Tibet Autonomous Region to the north and east,

and Bhutan to the southeast, while the state of West Bengal lies to the south. Sikkim

is the second smallest state of India. It is the home of Mahayana form of Buddhism

and its colourful Gompas (Buddhist monasteries) are the major sites of attraction. The

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INTRODUCTION

3

state is nonetheless geographically diverse due to its location in the Himalayas. It is a

popular tourist destination, owing to its culture, scenery and biodiversity. Kalimpong,

Lava and Lolegaon are famous hill station of West Bengal as a part of Eastern

Himalaya. These regions are also rich in its flora and fauna.

Geography:

Sikkim, which is situated in the eastern Himalayas, from longitude 88°03'40" to

88°57'19" East and from latitude 27º03'47" to 28º07'34" North. It has a total area of

7,096 km2, 114 km from north to south and 64 km from east to west. The entire state

is mountainous, with altitudes ranging from 1,000 to 28,170 ft. There are 440 villages,

eight towns and four districts in Sikkim. The genetic diversity, of both forest

vegetation and agricultural crops, is enormous. The state has about 600 plant species

and more than 4,000 species of flowering plants.

Kalimpong is situated in the lower part of Eastern Himalaya between 27.06°N

88.47°E. Total area of this region is 1,056.5 km2 with an average elevation of 4,091 ft.

Delo, the highest point in Kalimpong, has an elevation of 5,591 ft.

Lava is situated 34 km away from Kalimpong on the east way at an elevation of 7,200

ft. at 27.05°N 88.39°E. Lolegaon is a small village under Darjeeling district of West

Bengal state 12 km away from Lava.

Climate:

The climate of Eastern Himalaya varies from the Sub-tropical to the Alpine depending

upon the altitude (Sub-tropical up to 5000 ft: Temperate-5000-6500 ft; Alpine up to

13000 ft; snowline at 16000 ft and above). The temperature varies with altitude and

the slope (generally 6 degree to 10 degree). The tundra-type region in the north is clad

by snow for four months every year, and the temperature drops below 0°C (32°F)

almost every night. The peaks of north-western Sikkim are perpetually frozen. Most

of the inhabited regions of Eastern Himalaya, however, experience

a temperate climate, with the temperatures seldom exceeding 28°C (82°F) in summer

or dropping below 0°C (32°F) in winter; the mean monthly summer temperature is

15°C. The state has five seasons: winter, summer, spring, autumn, and

a monsoon season between June and September. The average annual temperature is

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INTRODUCTION

4

around 18°C (64°F). The relative humidity remains above 70 per cent throughout the

year at most places. The area experiences a heavy rainfall due to its proximity with

the Bay of Bengal. The rainfall in Northern part is comparatively less than that of the

other regions. Pre-monsoon rain occurs in April-May and monsoon operates normally

from the month of May and continues up to early October. July is the wettest month

in most of the places. The mean annual rainfall is minimum at Thangu (82 mm) and

maximum at Gangtok (3494 mm). There is an area in the North-West Sikkim, which

gets very little rainfall (even less than 4.9 mm.). This area has mainly snow-covered

mountains. Sikkim is one of the few states in India to receive regular snowfall.

The snow line ranges from 20,000 ft in the north of the state to 16,000 feet in the

south. During the monsoon, heavy rains increase the risk of landslides. In the northern

region, because of the high altitude, temperatures can drop below -40°C (-40°F) in

winter. Fog affects many parts of the state during winter and the monsoons, making

transportation perilous.

Flora and fauna:

Eastern Himalaya including Sikkim and its adjoining regions are situated in an

ecological hotspot of the lower Himalayas, one of only three among the eco-regions

of India. The forested regions of the state exhibit a diverse range of fauna and flora.

Owing to its altitudinal gradation, the state has a wide variety of plants, from tropical

species to temperate, alpine and tundra ones, and is perhaps one of the few regions to

exhibit such diversity within such a small area. Nearly 81% of the area of Sikkim

comes under the administration of its forest department.

Sikkim has around 5,000 flowering plants, 515 rare orchids, 60 Primula species, 36

Rhododendron species, 11 oak varieties, 23 bamboo varieties, 16 conifer species, 362

types of ferns and ferns allies, 8 tree ferns, and over 424 medicinal plants. A variant

of the Poinsettia, locally known as "Christmas Flower", can be found in abundance in

the mountainous state. The orchid Dendrobium nobile is the official flower of Sikkim,

while the rhododendron is the state tree.

Orchids, figs, laurel, bananas, sal trees and bamboo grow in the Himalayan

subtropical broad leaf forests of the lower altitudes of this area.

In the temperate elevations above 1,500 meters (4,900 ft) there are Eastern Himalayan

broadleaf forests, where oaks, chestnuts, maples, birches, alders, and magnolias grow

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INTRODUCTION

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in large numbers, as well as Himalayan subtropical pine forests, dominated by Chirr

pine.

The alpine-type vegetation is typically found between altitudes of 3,500 to 5,000

meters (11,500 to 16,000 ft). In lower elevations are found juniper, pine, firs,

cypresses and rhododendrons from the Eastern Himalayan subalpine conifer forests.

Higher up are Eastern Himalayan alpine shrub and meadows, home to a broad variety

of rhododendrons and wild flowers.

The fauna include the snow leopard, the musk deer, the Himalayan Tahr, the red

panda, the Himalayan marmot, the sparrow, the goral, the barking deer, the common

lemur, the Himalayan Black Bear, the clouded leopard, the Marbled Cat, the leopard

cat, the wild dog, the Tibetan wolf, the hog badger, the binturong, the jungle cat and

the civet cat. Among the animals more commonly found in the alpine zone are yaks,

mainly reared for their milk, meat, and as a beast of burden.

The avifauna include of the Impeyan pheasant, the crimson horned pheasant, the snow

partridge, the snow cock, the lammergeyer and griffon vultures, as well as golden

eagles, quail, plovers, woodcock, sandpipers, pigeons, Old World flycatchers,

babblers and robins. Sikkim has more than 550 species of birds, some of which have

been declared endangered.

Eastern Himalaya also has a rich diversity of arthropods, many of which remain

unstudied. As with the rest of India, the most studied group is that of the butterflies.

Of approximately 1,438 butterfly species found in the Indian subcontinent, 695 have

been recorded from Sikkim. These include the endangered Kaiser-i-hind, Yellow

Gorgon and the Bhutan Glory.

The primary concern of this work is to investigate how many desmids are growing in

this region along with their habitat and ecological preferences, reproductive

behaviors, indicators of pollution etc.

Study area informations:

The study area of this project includes the total Sikkim state and several regions of

Eastern Himalaya under North-Eastern states of India. Sikkim state is covered by

Darjeeling district of West Bengal on the south, Nepal on the west, Tibet on the north

and China on the east. There are four districts under this state (namely East district,

West district, North district, South district). The state is crossed by several rivers. The

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INTRODUCTION

6

main rivers of Sikkim are Teesta and Rangit. Besides, there are several small streams

(Khola) across the state. Several famous lakes are also there like Guru-Dongmar,

Changu, Khechoperi, Menemcho and Betang-cho. There are several small and large

waterfalls like Kanchanjungha, Rimbi falls, seven sisters’ falls, Changey waterfalls,

Backthong waterfalls, Bonjakhari waterfalls etc. These all are the places of interest for

the field collections. Because of the altitude that vary right from an altitude of 500 ft.

to summits that touch the skies, the flora and fauna naturally covers a wide spectrum –

tropical to the alpine. Sikkim’s botanical richness is awe-inspiring, boasting of more

than 4000 species of plants found in the Indian sub-continent. No wonder Sikkim has

been a dream of naturalists. Dr. J. Hooker during the middle of the last century

surveyed in detail the botanical wealth in Sikkim and his findings were embodied in

the publication “Himalayan Journal” that is still considered as an authoritative

document.

Only Kalimpong and Lava, Lolegaon, Rishop and its adjoining regions are studied

under this research programme. Kalimpong is a small town between Delo hill and

Durpin hill, Teesta river flows beside this town. This region also crossed by several

small streams and several small waterfalls and small water bodies are here and there

on its way. Delo reservoir is a polluted lake in Delo hills. Kalimpong is also rich in

its flora and fauna. Several rare species of fern, orchids, flowers and bryophytes are

present in the hilly regions. Most of its floral vegetation is still unexplored.

Lava is situated in 34 km. away from Kalimpong and is a small town under Darjeeling

district of West Bengal state. It is situated between 27.05°N 88.39°E with an

elevation of 7,200 ft. It is the entry point to the Neora Valley National Park which has

very diverse floral and faunal vegetation. Few water bodies are there in this region

which has very rich in microflora. Several waterfalls are there but Chage waterfall is

famous tourist attraction. Those areas are good habitats of water floras. Lolegaon is a

small village under Darjeeling district of West Bengal state 12 km away from Lava

and is a hill station for tourists. The adjoining regions are famous for its fern flora as

well as angiospermic flora.

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Review of

Literature

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REVIEW OF LITERATURE

7

REVIEW OF LITERATURE

In spite of enormous range of biodiversity very little work has been done on algal

diversity especially on desmids of Eastern Himalaya. Only a few investigations have

been carried out in this regard in last 130 years. Dickie (1882) is considered the

pioneer for the investigation of algae from this region. The algal samples were

collected by Dr. Watt during May & June 1881 from several pools and lakes in the

Upper Batong Valley of Sikkim at the altitude of 15,000-18,000 ft. from the sea level.

Studying these samples, Dickie reported 13 desmid taxa viz. Cosmarium (6 species),

Staurastrum (3 species), Hyalotheca (1 species), Tetmemorus (1 species), Penium (1

species) and Cylindrocystis (1 species). A long gap of 80 years after the work of

Dickie another phycological study was made by Rao (1963). In this study he reported

only one desmid taxa i.e. Cosmarium undulatum. Several other groups of algae were

also reported viz. diatoms (11 species), Cyanophyceae (1 species) and Chlorophyceae

(1 species other than desmid) from Lachen and Gnathong river, Sikkim during his

botanical tour in this state. Few works on the high altitude Cyanophyta from different

regions of Eastern Himalaya were carried out by Dutt et al. (1973, 1975 & 1976). On

the same time several species of Spirogyra, few members of Vaucheriaceae were

reported by Santra & Adhya (1973, 1976a & 1976b) from Eastern Himalaya. Santra

(1984) worked on the algal flora of Sikkim Himalaya. In this investigation he worked

out only the Cyanophycean flora of north-eastern part of Sikkim and reported 31 taxa

from different regions such as river bed, streams, soil surfaces, rock surfaces, tree

barks etc. Dominant genus was Lyngbya (8 species). First extensive work was done

by Prasad & Misra (1987) on desmids of Sikkim. In this study they reported 18

desmid species from different regions mainly from Gangtok and Singtam regions. The

desmid taxa reported in their study are Cylindrocystis (1 species), Penium (1 species),

Closterium (5 species), Cosmarium (10 species) and Staurastrum (1 species). Another

phycological study was made from Sikkim by Prasad & Khanna (1987). In this study

they reported Cyanophytes specially Oscillatoriaceae from different parts of Sikkim.

Total 24 members of Oscillatoriaceae were being studied of which majority are

represented by Oscillatoria (14 taxa). Prasad et al. (1988) may be considered the

pioneer workers in investigating the diatom flora of different regions of Kalimpong.

Probably the first phycological study in Shillong, Meghalaya was carried out by Rout

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REVIEW OF LITERATURE

8

& Gaur (1994) on the epilithic algal vegetation in a forest stream. They investigated

only 3 species of desmids namely Closterium (1 species), Cosmarium (1 species) and

Hyalotheca (1 species) along with other 2 taxa of Chlorophyceae, 79 taxa of

Bacillariophyceae, 11 taxa of Cyanophyceae and 1 member of Rhodophyceae. Jain et

al. (1999) during their study of hydrology and nutrient dynamics of “Khecheopalri”

lake reported one member of Cosmarium (species not identified) with 2 species of

other Chlorophycean members from this lake. Gupta (2002) prepared a checklist of

algae of Shilling, Meghalaya. In this checklist he recorded 16 species of desmids viz.

Arthrodesmus (1 species), Closterium (4 species), Cosmarium (3 species), Euastrum

(3 species), Mesotaenium (1 species), Micrasterias (2 species), Netrium (1 species) &

Staurastrum (1 species) and other 35 members of Chlorophyceae along with 13

members of Cyanophyceae, 21 members of Bacillariophyceae and 20 members of

Euglenophyceae. Kumar & Rai (2005) contributed to the algal flora of Namchi

region. They investigated 7 species of desmids in this region of which Closterium (4

species) was found dominant and Netrium, Cosmarium and Staurastrum were found

represented by one species each. 6 other Chlorophycean members were also reported

in this study. Extensive work has been done by Santra & Pal (2006) during their

phycological exploration to Sikkim and West Bengal during 1990 to 1995 covering

different habitats. They reported 214 species of desmid taxa of which 65 desmid

members have been reported from the Eastern Himalayan regions. Suseela & Toppo

(2006) enumerated the algae of Gangtok, the capital of Sikkim. They reported 45

species of Cyanophyceae, 8 species of diatoms, 1 Xanthophycean member and 14

Chlorophyceae of which only one desmid genera was represented Cosmarium (5 taxa)

from different places of Gangtok such as small ditches, ponds, water tanks etc. Das et

al. (2009) contributed to the freshwater algal flora of Meghalaya. In this investigation

they recorded 59 freshwater algal members from this region of which desmids

vegetation represented by 13 members viz. Closterium (3 species), Cosmarium (9

species) and Euastrum (1 species). Other algal members were Cyanophytes

represented by 3 taxa, diatoms by 28 taxa, Euglenophytes by 3 taxa and Chlorophytes

other than desmids by 12 taxa. Bhakta et al. (2010) enumerated 50 algal members

from different locations of Sikkim. In this work they investigated 17 members of

Chlorophyceae including the desmids represented by 5 members viz. Cosmarium (4

species) and one species of Cylindrocystis along with 19 species of Cyanophyceae

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and 14 species of Bacillariophyceae. Deca et al. (2011) made a checklist of desmids

of Urpad Beel of Assam. In this work they included 14 genera of desmids with 91

species viz. Cosmarium (41 species), Closterium, (14 species), Euastrum (12 species),

Desmidium (3 species), Micrasterias (2 species), Staurastrum (7 species),

Actinotaenium (3 species), Xanthidium (2 species), Netrium (2 species), Hyalotheca

(1 species), Haplotaenium (1 species), Spondylosium (1 species), Bambusina (1

species) and Staurodesmus (1 species). Yasmin et al. (2011) reported 38 desmids taxa

from different regions of eastern Himalaya and reported 8 species of Closterium, 10

species of Cosmarium, 5 species each of Euastrum, Micrasterias and Staurastrum, 2

species of Pleurotaenium¸ 1 species each of Netrium, Tortitaenia and Gonatozygon

during their study period from August 2009 to 2010. Recently Das & Keshri (2012)

recorded 12 taxa from Mamencho Lake, a high altitude lake in Eastern Himalaya. In

this work 5 genera viz. Closterium (5 taxa), Cosmarium (4 taxa), Netrium (1 taxa),

Penium (1 taxa) and Hyalotheca (1 taxa) have been investigated of which 5 taxa have

been recorded as new to Indian flora.

Considering the fact that our knowledge about the algae & desmids in particular is

poor in Eastern Himalaya this study has been taken. An updated list of desmids

recorded from Eastern Himalaya is given in this table below.

Name of the species Locality Investigators

1 Actinotaenium crassiusculum (De

Bary) Teiling

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

2 Actinotaenium cruciferum (De

Bary) Teiling

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

3 Actinotaenium subglobosum

(Nordstedt) Teiling

Tsungthang Santra & Pal (2006)

4 Actinotaenium turgidum

(Brébisson ex Ralfs) Teiling

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

5 Arthrodesmus curvatus Turner Shillong, Meghalaya Gupta (2002)

6 Bambusina borreri (Ralfs) Cleve Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

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Name of the species Locality Investigators

7 Closterium abruptum West Manmecho

(Mamencho) lake,

Sikkim

Das & Keshri

(2012)

8 Closterium abruptum West var.

brevius West et GS West

Manmecho

(Mamencho) lake,

Sikkim

Das & Keshri

(2012)

9 Closterium acerosum (Schrank)

Ehrenberg var. elongatum

Brébisson

Water spring at

Namchi

Kumar & Rai

(2005)

10 Closterium acerosum Ehrenberg

ex Ralfs

Gangtok (Sikkim) Prasad & Misra

(1987)

Shillong, Meghalaya Rout & Gaur (1994)

Gangtok, Ghum,

Mirik, Mongon,

Tonglu

Santra & Pal (2006)

11 Closterium acutum (Lyngb.) de

Brébisson ex Ralfs var. variabile

(Lemmermann) Kreiger

Eastern Himalaya Yasmin et al.

(2011)

12 Closterium acutum Brébisson in

Ralfs

Shillong, Meghalaya Gupta (2002)

13 Closterium arcuarium Hughes Manmecho

(Mamencho) lake,

Sikkim

Das & Keshri

(2012)

14 Closterium closterioides (Ralfs)

Louis et Peeters var. intermedium

(Roy et Bisset) Ruzicka

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

Eastern Himalaya Yasmin et al.

(2011)

15 Closterium costatum Corda ex

Ralfs

Eastern Himalaya Yasmin et al.

(2011)

16 Closterium cynthia De Notoris Mongon, Mongpoo,

Tonglu

Santra & Pal (2006)

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Name of the species Locality Investigators

17 Closterium dianae Ehrenberg Mirik, Nayabazar,

Pemayangtse

Santra & Pal (2006)

18 Closterium dianae Ehrenberg var.

pseudoleibleinii Förster et Eckert

Shillong, Meghalaya Gupta (2002)

19 Closterium eborecense

(Ehrenberg) Turner

Gangtok (Sikkim) Prasad & Misra

(1987)

Ghum, Sandakphu,

Rimbick

Santra & Pal (2006)

20 Closterium ehrenbergii

Meneghini ex Ralfs

Stream in Shillong Das et al. (2009)

Eastern Himalaya Yasmin et al.

(2011)

21 Closterium incurvum Brébisson Eastern Himalaya Yasmin et al.

(2011)

22 Closterium kuetzingii Brébisson

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

Eastern Himalaya Yasmin et al.

(2011)

23 Closterium leibleinii Kutzing ex

Ralfs

Mirik, Tonglu Santra & Pal (2006)

24 Closterium leibleinii Kützing var.

recurvatum West et GS West

Kurseong, Mongpoo Santra & Pal (2006)

25 Closterium libellula Focke var.

intermedium (Roy et Bissett) GS

West

Gangtok (Sikkim) Prasad & Misra

(1987)

Mongpoo,

Sandakphu, Lachen,

Darjeeling,

Santra & Pal (2006)

26 Closterium lundellii Lagerheim

var. ellipticum West et GS West

Waterfalls at

Namchi towards

Namthang

Kumar & Rai

(2005)

27 Closterium lunula (Muller)

Nitzsch var. biconvexum

Schmidle

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

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Name of the species Locality Investigators

28 Closterium lunula (Muller)

Nitzsch var. massartii (De

Wildeman) Krieger

Waterfalls at

Namchi towards

Namthang

Kumar & Rai

(2005)

29 Closterium lunula Ehrenberg et

Hemprich ex Ralfs

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

30 Closterium moniliferum (Bory)

Ehrenberg var. concavum Klebs

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

31 Closterium moniliferum (Bory)

Ehrenberg var.

malinvernianiforme (Grönblad)

Kossinskaja

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

32 Closterium moniliforme (Bory)

Ehrenberg

Gangtok (Sikkim) Prasad & Misra

(1987)

Shillong, Meghalaya Gupta (2002)

33 Closterium navicula (Brébisson)

Lütkemüller

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

34 Closterium parvulum Nägeli

Stream in Jayantia

hills

Das et al. (2009)

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

35 Closterium parvulum Nägeli var.

maius (Schmidle) Krieger

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

36 Closterium peracerosum Gay var.

elegans GS West

River in Shimit Das et al. (2009)

37 Closterium planum Hughes Manmecho

(Mamencho) lake,

Sikkim

Das & Keshri

(2012)

38 Closterium praelongum Brébisson Eastern Himalaya Yasmin et al.

(2011)

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Name of the species Locality Investigators

39 Closterium pritchardianum

Archer

Gangtok (Sikkim) Prasad & Misra

(1987)

40 Closterium pseudodianae Roy Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

41 Closterium pseudolunula Borge Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

42 Closterium striolatum Ehrenberg

var. subtruncatum (West et GS

West) Krieger

Manmecho

(Mamencho) lake,

Sikkim

Das & Keshri

(2012)

43 Closterium tumidum Johnson var.

nylandicum Grönblad

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

44 Closterium tumidum West Pond near Namchi

towards Jorthang

Kumar & Rai

(2005)

45 Closterium turgidum Ehrenberg

ex Ralfs

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

46 Closterium ulna Focke ex Turner Ghum, Darjeeling Santra & Pal (2006)

47 Closterium venus Kutzing var.

debegenica Cholnoky

Kalimpong Santra & Pal (2006)

48 Closterium venus Kutzing var.

incurvum (Brébisson) Krieger

Eastern Himalaya Yasmin et al.

(2011)

49 Closterium venus Kützing ex

Ralfs

Shillong, Meghalaya Gupta (2002)

50 Cosmarium depressum (Nägeli)

Lundell

Stream at Gangtok

(Sikkim)

Suseela & Toppo

(2006)

51 Cosmarium abbreviatum

Raciborski

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

52 Cosmarium aeguale Turner var.

nepalense Hirano

Lachen, Lachung Santra & Pal (2006)

53 Cosmarium amoenum Brébisson

ex Ralfs

Shillong, Meghalaya Gupta (2002)

54 Cosmarium anceps Lundell Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

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Name of the species Locality Investigators

55 Cosmarium aphanichondrum

Nordstedt

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

56 Cosmarium awadhense Prasad et

Mehrotra

Small ditch at

Gangtok (Sikkim)

Suseela & Toppo

(2006)

Stream in Shillong Das et al. (2009)

57 Cosmarium binum Nordstedt Kalimpong, Lava,

Tista bazaar

Santra & Pal (2006)

58 Cosmarium bioculatum Brébisson

ex Ralfs

Shillong, Meghalaya Rout & Gaur (1994)

Stream in Shillong Das et al. (2009)

59 Cosmarium bipunctatum

Børgesen

Mirik, Nayabazar

Tonglu, Rimbick

Santra & Pal (2006)

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

60 Cosmarium bipunctatum

Borgesen f. subrectangularis

West et GS West

Gangtok (Sikkim) Prasad & Misra

(1987)

61 Cosmarium botrytis (Meneghini)

Ralfs var. mediolaeve West

Gangtok (Sikkim) Prasad & Misra

(1987)

62 Cosmarium botrytis Meneghini ex

Ralfs

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

63 Cosmarium brebissonii

Meneghini ex Ralfs

Upper Batong

Valley

Dickie (1882)

64 Cosmarium ceylanicum W et GS

West

Mongpoo, Tiger hill Santra & Pal (2006)

65 Cosmarium circulare Reinsch

Shillong, Meghalaya Gupta (2002)

Tsungthang Santra & Pal (2006)

66 Cosmarium circulare Reinsch

var. messikommeri Krieger et

Gerloff

Singtam (Sikkim) Prasad & Misra

(1987)

67 Cosmarium connatum Brébisson

ex Ralfs

Kalimpong, Namchi,

Nayabazar, Phalut

Santra & Pal (2006)

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Name of the species Locality Investigators

68 Cosmarium constractum Delponte

var. ellipsoidum West et GS West

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

69 Cosmarium contractum Kirchner

Shillong, Meghalaya Gupta (2002)

Stream in Jayantia

hills

Das et al. (2009)

70 Cosmarium controversum West Mongpoo Santra & Pal (2006)

71 Cosmarium crassipelle Flint et

Williamson var. noduliferum Flint

et Williamson

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

72 Cosmarium cucumis Corda ex

Ralfs var. magnum Raciborski

Eastern Himalaya Yasmin et al.

(2011)

73 Cosmarium cucurbitinum (Bisset)

Lütkemüller var.

subpolymorphum (Nordstedt)

Teiling [Now considered as

Actinotaenium cucurbitinum

(Bisset) Teiling]

Singtam (Sikkim) Prasad & Misra

(1987)

74 Cosmarium curcurbita Brébisson

ex Ralfs (now considered as

Actinotaenium

curcurbita(Brébisson) Teiling ex

Ruzicka & Pouzar

Reservoir in

Maplong

Das et al. (2009)

75 Cosmarium cyclicum Lundell Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

76 Cosmarium cyclicum Lundell var.

nordstedtianum (Reinsch) West et

GS West

Small ditch at

Gangtok (Sikkim)

Suseela & Toppo

(2006)

77 Cosmarium cyclicum Lundell ver.

arcticum (Nordstedt) Westet GS

West

Sandakphu,

Mongpoo, Lava,

Yoksum

Santra & Pal (2006)

78 Cosmarium decoratum West et

GS West

Changu lake Bhakta et al. (2010)

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Name of the species Locality Investigators

79 Cosmarium depressum (Nageli)

Lundell

Nayabazar,

Gangtok,

Tsungthang

Santra & Pal (2006)

80 Cosmarium didymoprotupsum

West et GS West

Gangtok (Sikkim) Prasad & Misra

(1987)

81 Cosmarium dubium Borge Singtam (Sikkim) Prasad & Misra

(1987)

82 Cosmarium favum West et GS

West

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

83 Cosmarium formosulum Hoffman

Nayabazar, Mirik,

Tonglu, Tiger hill

Santra & Pal (2006)

Hanuman tok

(Sikkim)

Bhakta et al. (2010)

84 Cosmarium garrolense Roy et

Bisset

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

Namchi, Darjeeling

Sandakphu, Rimbick

Santra & Pal (2006)

85 Cosmarium granatum Brébisson

ex Ralfs

Kalimpong, Tonglu,

Mongpoo

Santra & Pal (2006)

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

86 Cosmarium hammeri Reinsch Tsungthang,

Nayabazar

Santra & Pal (2006)

87 Cosmarium hammeri Reinsch var.

homalodermum (Nordstedt) West

et GS West

Small ditch at

Gangtok (Sikkim)

Suseela & Toppo

(2006)

88 Cosmarium hammeri Reinsch var.

protuberans West et GS West

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

89 Cosmarium humile Nordstedt ex

De Toni

Water tank near

Nehru Botanical

Garden (Sikkim)

Suseela & Toppo

(2006)

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Name of the species Locality Investigators

90 Cosmarium impressulum Elfving

Kurseong, Mongpoo Santra & Pal (2006)

Stream in Jayantia

hills

Das et al. (2009)

91 Cosmarium impressulum Elfving

var. suborthogonum (West et GS

West) Taft

Manmecho

(Mamencho) lake,

Sikkim

Das & Keshri

(2012)

92 Cosmarium isthmium West Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

93 Cosmarium kirchneri Børgesen Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

94 Cosmarium laeve Rabenhorst var.

octangulare (Wille) West et GS

West

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

95 Cosmarium lundelli Delponte

Singtam (Sikkim) Prasad & Misra

(1987)

Mongpoo, Ghum,

Lava, Phalut

Santra & Pal (2006)

96 Cosmarium majae Strøm Singtam (Sikkim) Prasad & Misra

(1987)

97 Cosmarium malinvernianum var.

badense Schmidle

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

98 Cosmarium margaritiferum

Meneghini ex Ralfs

Mongpoo, Mirik,

Lachen

Santra & Pal (2006)

99 Cosmarium minimum Ehrenberg

var. subrotundum West et GS

West

Manmecho

(Mamencho) lake,

Sikkim

Das & Keshri

(2012)

100 Cosmarium moniliforme Ralfs Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

101 Cosmarium montrealense

Croasdale

Manmecho

(Mamencho) lake,

Sikkim

Das & Keshri

(2012)

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Name of the species Locality Investigators

102 Cosmarium nobile (Turner)

Krieger

Eastern Himalaya Yasmin et al.

(2011)

103 Cosmarium obsoletum (Hantzsch)

Reinsch

Eastern Himalaya Yasmin et al.

(2011)

104 Cosmarium ocellatum Eichler et

Gutwinski

Eastern Himalaya Yasmin et al.

(2011)

105 Cosmarium ocellatum Eichler et

Gutwinski var. notatum

(Nordstedt) Krieger et Gerloff

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

106 Cosmarium ocellatum Eichler et

Gutwinski var. mamillatum

Hinode

Darjeeling, Tiger

hill

Santra & Pal (2006)

107 Cosmarium pachydermum

Lundell

Upper Batong

Valley

Dickie (1882)

108 Cosmarium phaseolus Brébisson

var. phaseolus f. minus Boldt

Manmecho

(Mamencho) lake,

Sikkim

Das & Keshri

(2012)

109 Cosmarium platydesmium

(Nordstedt) Schmidle

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

110 Cosmarium portianum Archer Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

Kalimpong,

Mongpoo

Santra & Pal (2006)

111 Cosmarium praecisum Borge Pastanga (Sikkim) Bhakta et al. (2010)

112 Cosmarium pseudamoenum Wille Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

113 Cosmarium pseudobroomei Wolle Stream in Jayantia

hills

Das et al. (2009)

Eastern Himalaya Yasmin et al.

(2011)

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Name of the species Locality Investigators

114 Cosmarium pseudoconnatum

Nordstedt

Darjeeling,

Kurseong,

Mongpoo, Phalut

Santra & Pal (2006)

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

115 Cosmarium pseudogranatum

Nordstedt var. rotundatum

(Krieger) Messikomer

Stream at Namchi Kumar & Rai

(2005)

116 Cosmarium pseudoprotuberans

Kirchner

Mirik Santra & Pal (2006)

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

117 Cosmarium pseudopyramidatum

Lundell

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

118 Cosmarium pseudoretusum

Ducellier var. africanum (Fritsch)

Krieger & Gerloff

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

119 Cosmarium punctulatum

Brébisson

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

120 Cosmarium punctulatum

Brébisson var. subpunctulatum

(Nordstedt) Børgesen

Tsungthang, Tonglu,

Ghum

Santra & Pal (2006)

121 Cosmarium pyramidatum

Brébisson ex Ralfs

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

122 Cosmarium quadratum Ralfs Namchi Santra & Pal (2006)

123 Cosmarium quadratum Ralfs var.

willei (Schmidle) Krieger et

Gerloff

Gangtok (Sikkim) Prasad & Misra

(1987)

124 Cosmarium quadrifarium Lundell

et var. hexastichum (Lundell)

Förster

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

125 Cosmarium quadrifarium Lundell

et var. oblonga Kant et Gupta

Pastanga (Sikkim)

Bhakta et al. (2010)

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Name of the species Locality Investigators

126 Cosmarium quadrum Lundell

Mongpoo, Lava,

Phalut

Santra & Pal (2006)

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

Eastern Himalaya Yasmin et al.

(2011)

127 Cosmarium quadrum Lundell var.

minus Nordstedt

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

128 Cosmarium rectangular

Brébisson var. subhexagonum

Playfair

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

129 Cosmarium regulare Schmidle Darjeeling, Lava,

Pmayangtse,

Santra & Pal (2006)

130 Cosmarium reniforme (Ralfs)

Archer

Eastern Himalaya Yasmin et al.

(2011)

131 Cosmarium retusiforme (Wille)

Gutwinski

Stream in Jayantia

hills

Das et al. (2009)

132 Cosmarium retusum (Perty)

Rabenhorst var. angustatum

(West) West et GS West

Sandakphu, Phalut Santra & Pal (2006)

133 Cosmarium scabratulum West et

GS West

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

134 Cosmarium scabrolatum Turner Eastern Himalaya Yasmin et al.

(2011)

135 Cosmarium speciosissimum

Schmidle

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

136 Cosmarium speciosum Lundell

Kalimpong, Ghum,

Mongon, Tonglu

Santra & Pal (2006)

Stream in Jayantia

hills, Jowai

Das et al. (2009)

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

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Name of the species Locality Investigators

137 Cosmarium subauriculatum West

et GS West

Ghum Santra & Pal (2006)

138 Cosmarium subcostatum

Nordstedt

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

139 Cosmarium subcrenatum

Hantzsch

Kurseong Santra & Pal (2006)

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

140 Cosmarium subprotumidum

Nordstedt

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

141 Cosmarium subspeciosum

Nordstedt

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

142 Cosmarium subtumidum

Nordstedt f. minor Strom

Kurseong,

Kalimpong, Mirik,

Mongon

Santra & Pal (2006)

143 Cosmarium subtumidum

Nordstedt

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

144 Cosmarium subturgidum (Turner)

Schmidle

Singtam (Sikkim) Prasad & Misra

(1987)

145 Cosmarium tetragonum (Nägeli)

Archer

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

146 Cosmarium trilobulatum Reinsch Eastern Himalaya Yasmin et al.

(2011)

147 Cosmarium turgidum Brébisson

in Ralfs var. westii (Bernard)

Krieger et Gerloff

Reservoir in

Maplong

Das et al. (2009)

148 Cosmarium undulatum Corda ex

Ralfs

Gnathong river

(Sikkim)

Rao (1963)

149 Cosmarium vittatum Turner Eastern Himalaya Yasmin et al.

(2011)

150 Cosmarium wittrockii Lundell Darjeeling Santra & Pal (2006)

151 Cosmarium wuhanense Wei et Yu Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

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Name of the species Locality Investigators

152 Cylindrocystis brebissonii (Ralfs)

de Bary

Upper Batong

Valley

Dickie (1882)

Mongpoo, Phalut,

Rimbick, Senchal

lake

Santra & Pal (2006)

153 Cylindrocystis crassa Bary Gangtok (Sikkim) Prasad & Misra

(1987)

154 Cylindrocystis ovalis Turner Hanuman tok

(Sikkim)

Bhakta et al. (2010)

155 Desmidium aptogonum Brébisson

ex Kützing

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

156 Desmidium baileyi f. tetragona

Nordstedt

Tsungthang, Lachen,

Mongon

Santra & Pal (2006)

157 Desmidium bengalicum Turner Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

158 Desmidium coarctatum Nordstedt Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

159 Euastrum gnatophorum West et

GS West

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

160 Euastrum affine Ralfs ex Ralfs Shillong, Meghalaya Gupta (2002)

161 Euastrum ansatum Ehrenberg ex

Ralfs

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

162 Euastrum ansatum Ehrenberg ex

Ralfs var. pixidatum Delponte

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

163 Euastrum bidentatum Nägeli Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

164 Euastrum binale Ehrenberg ex

Ralfs

Darjeeling, Mirik,

Mongpoo, Mongon

Santra & Pal (2006)

165 Euastrum ceylanicum (West et

GS Wset) Krieger

Kurseong, Lava,

Namchi, Mongpoo,

Tonglu

Santra & Pal (2006)

Eastern Himalaya Yasmin et al.

(2011)

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Name of the species Locality Investigators

166 Euastrum didelta (Turpin) Ralfs

var. bengalicum Lagerheim

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

167 Euastrum didelta Turpin ex Ralfs Eastern Himalaya Yasmin et al.

(2011)

168 Euastrum dubium Nägeli

Namchi, Kurseong,

Mongpoo

Santra & Pal (2006)

Stream in Jayantia

hills, Jowai

Das et al. (2009)

169 Euastrum elegans Ralfs Eastern Himalaya Yasmin et al.

(2011)

170 Euastrum irregular Maskell Shillong, Meghalaya Gupta (2002)

171 Euastrum luetkemulleri Ducellier

var. carniolicum (Lütkemüller)

Krieger

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

172 Euastrum luetkemulleri Ducellier

var. floridanum Scott et Grönblad

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

173 Euastrum paradoxum Turner Eastern Himalaya Yasmin et al.

(2011)

174 Euastrum pseudotuddalense

Messikommer

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

175 Euastrum sphyroides Nordstedt

var. intermedium Lütkemüller

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

176 Euastrum spinulosum Delponte

Shillong, Meghalaya Gupta (2002)

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

Eastern Himalaya Yasmin et al.

(2011)

177 Euastrum spinulosum Delponte

var. inermius Nordstedt

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

178 Euastrum sublobatum Brébisson

var. incrassatum Scott et Prescott

Darjeeling Santra & Pal (2006)

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Name of the species Locality Investigators

179 Euastrum substellatum Nordstedt Kurseong Santra & Pal (2006)

180 Euastrum turneri West Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

181 Gonatozygon aculeatum Hasting Ghum, Sandakphu,

Tonglu

Santra & Pal (2006)

182 Gonatozygon kinahani (Archer)

Rabenhorst

Kalimpong, Lava Santra & Pal (2006)

Eastern Himalaya Yasmin et al.

(2011)

183 Haplotaenium minutum (Ralfs)

Bando

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

184 Hyalotheca dissiliens (Smith)

Brébisson ex Ralfs

Manmecho

(Mamencho) lake,

Sikkim

Das & Keshri

(2012)

Mongpoo,

Nayabazar, Lava

Santra & Pal (2006)

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

Shillong, Meghalaya Rout & Gaur (1994)

185 Hyalotheca dissiliens Brébisson ex

Ralfs var. tridentula Nordstedt

Upper Batong

Valley

Dickie (1882)

186 Mesotaenium degreyi Turner Shillong, Meghalaya Gupta (2002)

187 Micrasterias apiculata Meneghini

ex Ralfs

Eastern Himalaya Yasmin et al.

(2011)

188 Micrasterias foliacea Bailey ex

Ralfs

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

189 Micrasterias incisa Ralfs Eastern Himalaya Yasmin et al.

(2011)

190 Micrasterias mahabuleshwarensis

Hobson var. wallichii (Grunow)

West et GS West

Eastern Himalaya Yasmin et al.

(2011)

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Name of the species Locality Investigators

191 Micrasterias pinnatifida Ralfs

Shillong, Meghalaya Gupta (2002)

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

Eastern Himalaya Yasmin et al.

(2011)

192 Micrasterias zeylanica Fritsch

Shillong, Meghalaya Gupta (2002)

Eastern Himalaya Yasmin et al.

(2011)

193 Netrium digitus (Brébisson ex

Ralfs) Itzigsohn et Rothe

Eastern Himalaya Yasmin et al.

(2011)

Shillong, Meghalaya Gupta (2002)

Water spring at

Namchi

Kumar & Rai

(2005)

Namchi, Nayabazar Santra & Pal (2006)

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

194 Netrium digitus (Brébisson ex

Ralfs) Itzigsohn et Rothe var.

lamellosum (Brébisson ex

Kützing) Grönblad

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

195 Netrium interruptum (Brébisson

ex Ralfs) Lütkemüller var. minor

(Borge) Krieger

Manmecho

(Mamencho) lake,

Sikkim

Das & Keshri

(2012)

196 Onychonema leave Nordstedt var.

latum West et GS West

Kurseong, Lachung Santra & Pal (2006)

197 Onychonema leave Nordstedt var.

sumatranum Scott et Prescott

Pmayangtse,

Yoksum

Santra & Pal (2006)

198 Penium digitus Brébisson ex

Ralfs

Upper Batong

Valley

Dickie (1882)

199 Penium margaritaceum

(Ehrenberg) deBrébisson ex Ralfs

Manmecho

(Mamencho) lake,

Sikkim

Das & Keshri

(2012)

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Name of the species Locality Investigators

200 Penium minutum (Ralfs) Cleve

var. crassum West

Gangtok (Sikkim) Prasad & Misra

(1987)

201 Pleurotaenium ehrenbergii

(Ralfs) Delponte

Eastern Himalaya Yasmin et al.

(2011)

Tonglu, Kalimpong,

Namchi

Santra & Pal (2006)

202 Pleurotaenium trabecula Nägeli Eastern Himalaya Yasmin et al.

(2011)

203 Pleurotaenium truncatum

(Brébisson) Nageli

Kurseong,

Tsungthang

Santra & Pal (2006)

204 Spondylosium nitens (Wallich)

Archer f. majus Turner

Sandakphu, Phalut,

Rimbick

Santra & Pal (2006)

205 Spondylosium planum (Wolle)

West et GS West

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

206 Staurastrum borgeanum Schmidle Pmayangtse,

Yoksum

Santra & Pal (2006)

207 Staurastrum crenulatum (Nägeli)

Delponte

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

208 Staurastrum curvatum West Shillong, Meghalaya Gupta (2002)

209 Staurastrum froficulatum Lundell Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

210 Staurastrum furcatum

(Ehrenberg) Brébisson f. richae

Croasdale

Kurseong, Sanchal

lake, Tiger hill

Santra & Pal (2006)

211 Staurastrum leave Ralfs Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

212 Staurastrum manfeldtii Delponte, Eastern Himalaya Yasmin et al.

(2011)

213 Staurastrum mucronatum Ralfs ex

Ralfs

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

214 Staurastrum opimum Turner Eastern Himalaya Yasmin et al.

(2011)

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Name of the species Locality Investigators

215 Staurastrum pachyrhynchum

Nordstedt

Stream at Namchi Kumar & Rai

(2005)

Eastern Himalaya Yasmin et al.

(2011)

216 Staurastrum polymorphum

Brébisson

Ghum Santra & Pal (2006)

217 Staurastrum polytrichum (Perty)

Rabenhorst

Eastern Himalaya Yasmin et al.

(2011)

218 Staurastrum punctulatum

Brébisson in Ralfs

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

219 Staurastrum retusum Turner Eastern Himalaya Yasmin et al.

(2011)

220 Staurastrum sexangulare

(Bulneim) Lundell var.

productum Nordstedt

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

221 Staurastrum subpygmeaum West

var. subangulatum West et GS

West

Gangtok (Sikkim) Prasad & Misra

(1987)

222 Staurastrum tohopekaligense

Wolle

Mongpoo Santra & Pal (2006)

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

223 Staurodesmus convergens

(Ehrenberg ex Ralfs) Lilleroth

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

224 Staurodesmus curvatus (Turner)

Thomasson var. latus (Scott et

Prescott) Thomasson

Darjeeling Santra & Pal (2006)

225 Staurodesmus dejectus

(Brébisson) Teiling

Ghum Santra & Pal (2006)

226 Staurodesmus dickiei (Ralfs)

Teiling var. microspinus Hinode

Kurseong Santra & Pal (2006)

227 Tetmemorus granulatus Brébisson

ex Ralfs

Upper Batong

Valley

Dickie (1882)

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Name of the species Locality Investigators

228 Tetmemorus laevis (Kützing)

Ralfs

Darjeeling Santra & Pal (2006)

229 Tortitaenia obscura (Ralfs) Brook Eastern Himalaya Yasmin et al.

(2011)

230 Xanthidium antilopaeum

(Brébisson) Kutzing

Namchi Santra & Pal (2006)

231 Xanthidium burkillii West et GS

West

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

232 Xanthidium urniforme (West et

GS West) Scott et Croasdale

Urpad beel area,

Goalpara, Assam

Deca et al. (2011)

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Material and

Methods

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MATERIAL AND METHODS

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MATERIAL AND METHODS

Collection of samples in the field:

Algal specimens, on which the present research work is based, were collected from

almost all accessible localities of 4 districts of Sikkim and several places of eastern

Himalaya like Kalimpong, Lava, Lolegaon, Rishop etc. Every effort has been made to

reach the remote areas of Eastern Himalaya. Extensive field work has been done in

almost all the seasons at every accessible locality. In several occasion repeated visits

were made to the same locality to get the clear picture of desmids population. Total

collections were made covering almost every season during April 2009 to January

2012. Total 1000 samples were collected during the entire study period. Water bodies

like lakes, drains, ditches, pokhries, rock pools provided rich phytoplankton flora in

comparison to those found in flowing water like waterfalls, streams and rivers. All

possible collections were also made: from every possible habitat whether free

floating, attached, lodged or otherwise. Algal members were found attached on lentic

soil surfaces, submerged or semi-submerged weeds and aquatic plants, and also

recorded from sub-aerial habitats. Phytoplankton found lodged on the submerged

aquatic weeds were also considered for collection. Green film or layer attached on the

decayed plant parts such as leaves, tree trunks etc were also considered. Collections

were also made from wet soil surfaces. Mucilaginous masses and balls were collected

from wet rock surfaces beside the streams and waterfalls. A number of collections

were also made from the habitat in associations with mosses. Bog-pools were found to

be the ideal collecting areas for the desmid samples. Wet mosses were collected from

tree bark, wet soil, rocks were also considered for collection of phytoplankton sample.

This is because moisture associated with mosses growing in damp situations is good

source of algae. Freshly collected samples were preserved in FAA solution on the

collection spot instantly in polythene bags with zipper, tagged and brief ecological

notes recorded in field data book. In case of epiphytic specimens the names of the

host plants were also noted. Water samples were preserved in Lugols’ iodine solution

for better preservation and proper precipitation. Ecological parameters such as colour

and nature of the specimen, habit, habitat, association, water and air temperature and

pH (standard universal pH indicator of Merck) were recorded.

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MATERIAL AND METHODS

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Preservation of the samples:

All the collected specimens were preserved in FAA solution. The chemical

composition of FAA for 1000 ml. is given below:

40% commercial formaldehyde: 100cc.

50% Ethyl alcohol: 500 cc.

Glacial acetic acid: 50 cc.

Distilled water: 350 cc.

To every 1000 ml. of this solution 50 cc. of glycerin was added to avoid the complete

desiccation.

In case of water samples Lugols’ Iodine solution was used. The composition of

Lugols’ Iodine is given below:

In 100 ml. distilled water following chemicals were added-

Potassium Iodide: 10 gms.

Iodine: 5 gms.

Glacial acetic acid: 9.5 ml.

Lugols’ Iodine solution was added directly to the water samples in 1% ratio.

Laboratory procedure:

After bringing the collected specimen in the laboratory all the samples were stored in

60 ml. amber coloured vials with proper labeling for further workout.

Microscopic observations and Camera Lucida drawings:

Microscopic observations of the collected materials were made as soon as possible.

Proper figures of the desired algal samples were drawn under appropriate

magnifications with the help of a drawing prism considering all the features present

there in. Measurements were taken properly with an ocular scale fitted within the

eyepiece of the microscope, previously standardizing for this purpose. Several

permanent slides of each specimen were made for further references and

photomicrography.

Preparation of Permanent Slides:

Standard procedure was followed in the preparation of the mounting specimen as

permanent slides. Small amount of specimens were mounted in dry slide (Bluestar)

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MATERIAL AND METHODS

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using GFW [Glycerin: Formalin: Distilled water 1:1:1 - (Bando, 1988)] as mounting

medium and covered by cover glass (Bluestar). Iodine solutions were sometimes used

to check the mucilage accumulation around the cell wall of the desmids. The slides

were sealed with synthetic enamel paint and kept for drying whole day inside a

petridish to avoid dust. After drying a second coating was applied. Third coating is

also required for long time storage.

Photomicrography:

Photomicrographs were taken from the permanent slides using Carl Zeiss Axiostar

plus research microscope with Nikon SLR model (D60) digital camera attachment

system.

All the collections have been kept in the Algal Herbarium of the department of

Botany, The University of Burdwan (BURD).

Identifications of the workout taxa were done properly consulting the standard

literatures and several monographs.

Measurement of Angle of Divergence for the identification of Closterium:

The angle of curvature or angle of divergence (DA) of Closterium species measured

by Closteriometer as proposed by Pentecost (1984), the mathematical equation is

given below

DA = 2tan−1 𝑥

𝑥2 + 𝑦2

2𝑦 − 𝑦

x & y can be measured after camera-lucida drawing of Closterium cell under

microscope.

Another equation was given by Nishihama (1972). According to him,

Divergence angle = tan 𝛼

4 =

𝑑 2

d & h can be measured after camera-lucida

drawing of Closterium cell under microscope.

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MATERIAL AND METHODS

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Identification of the desmids:

Desmid members that have been worked out were properly identified following the

standard monographs and literature (Ralfs 1848; Turner 1892; West & GS West 1904,

1905, 1908, 1912; West et al. 1923; Krieger 1937, 1939; Prescott et al. 1972, 1975,

1977, 1982; Croasdale et al. 1983; Ling & Tyler 1986; Lenzenweger 1996, 1997,

1999, 2003).

COLLECTION BRIEFS:

1st Trip – 14th April, 2009 to 20th April, 2009.

Collection areas: West Sikkim [Pelling and adjoining areas, Rimbi falls, Khechoperi

lake, Kangchendzonga falls, Yuksam and adjoining areas viz. Karthok lake,

Phamrong Falls]

Total Collection: 248 samples.

2nd Trip – 8th May, 2009 to 14th May, 2009

East Sikkim: Gangtok and adjoining areas (Ranipoal, Jalikhola, Rumtek, Jawaharlal

Nehru Botanical Garden, Bonjakhri falls, Backthang falls, Kaji Road, Chanmari,

Ganeshtok, Himalayan Zoological park) and Changu lake (Tsamgo lake).

Total Collection: 242 samples.

3rd Trip – 4th November, 2009 to 13th November, 2009

Collection areas: West Sikkim: Gangtok and adjoining areas [Bonjakhri falls,

Backthang falls], Changu Lake, Baba Mandir & adjoining areas, Bidang-Cho Lake,

Manmecho Lake.

West Sikkim: Pelling and adjoining areas [Rhabdense Ruin, Kanchanjungha

waterfalls, Rimbi waterfalls, Khechoperi Lake, Changey waterfalls], Dentam river,

Dentam and adjoining areas, Sordum, Singsore, Uttarey and adjoining areas, Sungure.

South Sikkim: Namchi and adjoining areas [Samdrupse]

Total Collection: 220 samples.

4th Trip – 1st May, 2010 to 6th May, 2010

Collection areas: North Sikkim [Singtam, Kabi, Naga waterfalls, Guru-Dongmar Lake

and its adjoining areas, Lachung and its adjoining areas, Katao, Yumthang,

Chungthang]

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MATERIAL AND METHODS

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Total Collection: 155 samples.

5th Trip – 21st January, 2012 to 31th January, 2012

Collection areas: Kalimpong and its adjoining areas [Delo park, Delo reservoir,

Mongpu], Lava and its adjoining areas [Rochella pass, Chage falls], Lolegaon, Rishop

and its adjoining areas.

Total collection: 139 samples.

Lakes and waterfalls visited:

Sikkim is famous for its lakes. Therefore attempts were made to investigate some of

them.

1) A small lake, besides the road towards Rhabdense Ruin, Upper Pelling. pH 5-5.5,

temp. 19°C, little polluted. Altitude: 6,800 ft.

2) Chonam Cho Lake, R. Ruin, U. Pelling. pH 5, temp. 21°C, clear water. Altitude:

6,800 ft.

3) Khechoperi Lake. pH 5-5.5, temp. 17°C, clear water, associated with Sphagnum

bogs. Altitude: 6,000 ft.

4) Small drain, adjoined to Khechoperi Lake, Pelling. pH 5, temp. 17°C, drain with

several aquatic, semi-aquatic, submerged small plants.

5) Karthak Lake, Yoksum, pH 5-5.5, temp. 19°C, small lake, unpolluted, clear water,

no plant adjoining the lake, Altitude: 5,840 ft.

6) Changu Lake, E. Sikkim. pH 6, temp. 6°C, unpolluted, clear water, several small

pokhri at the side of the river in few places, little slimy mass on the rocks.

Altitude: 12,310 ft.

7) Bidang-Cho Lake, Kupup. E. Sikkim, pH 6, temp. 10°C, greenish golden-algal

blooms appear. Altitude: 13,900 ft.

8) Manmecho Lake, E. Sikkim. pH 6, temp. 10°C, light green and dark green

filamentous scums appear. Altitude 14,000 feet.

9) Guru-Dongmar Lake, North Sikkim, pH 5.5, temp. 9°C, clear water, unpolluted.

Altitude: 17,800 ft.

10) Delo Reservoir, Delo Park, Kalimpong, pH 6-6.5, temp. 24°C polluted water, dark

greenish and grayish masses in the water of this reservoir. Altitude:

5,590 ft.

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MATERIAL AND METHODS

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11) Mach Pokhri, Mansong, pH 6.5, temp. 24°C More or less clear water, Light and

dark greenish filamentous and mucilaginous masses on the surface of the rock.

Eastern Himalaya mainly Sikkim is also distinguished for its waterfalls. Numerous

falls are spread in the state. In this project it is tried to illustrate most of them.

Rimbi falls, West Sikkim, pH 6, Temperature of the water 16°C.

Kanchanjongha falls, West Sikkim, pH 6. Temperature of the water 15°C.

Pharmong falls, West Sikkim, pH 5.5. Temperature of the water 15°C.

Bonjakhri falls, East Sikkim, pH 6.5. Temperature of the water 17°C.

Backthang falls, East Sikkim, pH 6. Temperature of the water 15°C.

Changey falls, West Sikkim, pH 6.5. Temperature of the water 14°C.

Naga falls, North Sikkim, pH 6. Temperature of the water 13°C.

Seven sisters fall, North Sikkim, pH 5.5. Temperature of the water 13°C.

Chage falls, Lava, West Bengal, pH. 6, Temperature of the water 18°C.

and many other small waterfalls

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Map of Sikkim and other regions of Eastern Himalaya depicting collection sites (in

red arrows) through the entire collection periods.

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Few pictures of collection spots:

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Ecology

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ECOLOGY

Desmids are exclusively freshwater algae in their distribution to natural waters. They

prefer mainly lentic habitats. They are scanty in lotic waters and Iceland habitats. The

highland bog pools however support desmids unique to such habitats. It is observed

that maximum species diversity occurs in acidic waters (pH 5-6.5). Ecological study

was targeted to the area to know the following:

(i) Phytosociological associations:

(ii) Physicochemical environments:

(i) Phytosociological associations: Desmids grow either in free-floating condition or

in association in gelatinous masses. Their associations with various angiosperms have

been highlighted by different desmidologists (Brook 1981). Detailed study was

therefore conducted in this line. It was observed that desmids grow in gelatinous

masses profusely with submerged aquatic angiosperms, mosses and few species of

grasses. It has also been noted that these angiosperms are almost always associated

with profuse desmid growth and good species diversity. The depth of water between

1/4-3.5 feet support abundant desmid growth around these aquatics. Some growth is

always noticed intimately associated with these macrophytes. It may therefore be

hypothesized that these plants secrete or release some growth supporting substances

suitable for desmid growth.

Plants surrounding desmid habitats are also unique. Several species of mosses

(Sphagnum, Taxithelium etc.) are good inhabitant of desmid flora. planktonic mosses

lodged on the clump of those mosses These plants grow in the wet areas of upper and

lower fringes of the slopes of water bodies as well as wet shady places on the rock or

on soil and on the bark of trees. The species of other group of algae such as

Mougeotia, Oedogonium, Spirogyra, Zygnema and a good number of

Chlorococcalean members like Pediastrum, Coelestrum, Scenedesmus and

Ankistrodesmus etc. have been frequently associated with desmids as mat or bloom on

the surface of the water.

It has been noted that the barren water bodies generally have very poor representation

of desmid flora. Surrounding vegetation and aquatic angiosperms have been found to

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have very strong influence on their distribution and diversity. As mentioned earlier

certain plants are always associated with the species diversity and richness of

desmids. This fact supports our observations. Temperature has a very good impact on

the proliferation of desmid biodiversity. The area under investigation holds a

temperature range of 10°C-25°C. Major and luxuriant growth supported in post-

monsoon and winter months (at a temperature range of 10°C-15°C).

It is interesting to note that some good samples carried more than 200 algal taxa,

mainly phytoplankton. Next to desmids, rest of the algal taxa belonged to

Chlorococcales, various species of unicellular and filamentous Cyanophyceae, several

good specimens of diatoms, a few filamentous and unicellular green algae and a few

Charophytes and Euglenophytes. Many more insignificantly and rarely occurring

algal forms belonged to unicellular members of Xanthophyceae, Chrysophyceae, and

Dinophyceae.

ii) Physico-chemical environments:

Sikkim is one of the great biodiversity hotspot in India. Several lakes are also

considered as the desmid hotspot of Sikkim. These are Bitang-cho lake, Mamencho

lake in the East Sikkim, Khechiperi lake, Kothag in Yoksum in the West Sikkim. Due

to time limits the investigations were however restricted to investigate only few

environmental parameters. viz.

1) Atmospheric temperature (°C)

2) Water temperature (°C)

3) pH

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Systematic Part

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SYSTEMATIC PART

Unicellular members of the order Zygnematales (Conjugales) are collectively known

as desmids. Desmids are unusual, interesting, microscopic group of algae which are

exclusively freshwater, no marine members have been reported yet. They are

unicellular, sometimes pseudo-filamentous (cells attached temporarily end to end

forming short filaments), majority are two parted, each of them termed as ‘semicells’

joined each other by ‘isthmus’. Each semicell contains one or more axial or parietal

chloroplast with different shape with single or more pyrenoids. Cell wall having

diverse ornamentation patterns which may be smooth, porous, sinulate, verrucate,

undulate, crenulate, striated, granulate etc. Reproduction occurs by conjugation with

amoeboid non-flagellate gametes forming thick-walled variously ornamented

zygospores.

Systematic arrangement of genera according to Brook (1981)

* Marked genera accommodated.

The saccoderm desmids

Zygnematales

Mesotaeniaceae

1. Ancylonema

2. Cylindrocystis

3. Mesotaenium

4. Netrium

5. Roya

6. Spirotaenia

7. Tortitaenia *

The placoderm desmids

Desmidiales

Gonatozygaceae

1. Gonatozygon

2. Genicularia

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Peniaceae

3. Penium

Closteriaceae

4. Closterium

Desmidiaceae

5. Actinotaenium

6. Arthrodesmus

7. Cosmarium

8. Desmidium

9. Euastrum

10. Haplotaenium *

11. Hyalotheca

12. Micrasterias

13. Onychonema

14. Pleurotaenium

15. Spondylosium

16. Staurastrum

17. Teilingia

18. Triplastrum

19. Triploceras

20. Xanthidium

Zygnematales: Saccoderm desmids

(Mesotaeniaceae)

Cells having cell wall consisting of single piece, shaped simple, cylindrical, spindle

shaped or fusiform, median constriction rarely present, pores or any ornamentation

absent.

Key to the genera described:

1. Cells having single chloroplast

2. Cells temporarily attached end to end forming short filament..….Ancylonema (I)

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2. Cells occurs singly not forming filament

3. Cells slightly curved, chloroplast with median notch…….......………Roya (V)

3. Cells straight, chloroplast without median notch…...…...…Mesotaenium (III)

1. Cells having more than one chloroplast

4. Cells longer, more than 5 times longer than broad

5. Chloroplast parietal, spiral or ribbon like……………..….…..Spirotaenia (VI)

5. Chloroplast axial, shaped otherwise

6. Cells cylindrical with tapering apex, chloroplast with radiating ridges

.........Netrium (IV)

6. Cells spindle shaped, chloroplast spiral, screw-shaped.......Tortitaenia (VII)

4. Cells stouter, less than 5 times longer than broad………….….Cylindrocystis (II)

I. Ancylonema Berggren

Cells small, cylindrical or sub-cylindrical, united loosely into short filaments made of

up to 4-15 cells. Lateral walls parallel, median incision absent, may be slightly retuse;

apex rounded or truncate with rounded angles. Chloroplast axial or parietal bands,

narrow with 1-2 pyrenoids. Cell wall smooth. Cell sap violet in colour.

1. Ancylonema nordenskioeldii Berggren

(Krieger 1937, p.203, pl. 5, f. 1, 2; Prescott et al. 1972, p. 13, pl. 3, f. 1-7)

[Pl. I, f. 1, 2]

Cells cylindric, 2-3 times longer than broad; the poles broadly rounded; cells

loosely adjoined end to end to form short filament; chloroplast axial, shaped a

narrow band with 1-2 pyrenoids.

Length: 15-17 µm, Breadth: 9-10 µm.

Collection No. DD-389, 16.09.2009, Bitang-cho Lake, Sikkim. In association

with green filaments on the surface of the water (pH 6, temp 10ºC).

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Indian distribution: This is probably the first report of the taxon from India.

II. Cylindrocystis Meneghini ex de Bary

Cells solitary, sometimes in a common gelatinous matrix, cylindrical, sub-cylindrical,

oblong or fusiform, straight or slightly curved, small to medium sized; median

constriction absent, lateral walls parallel, apex broadly rounded: chloroplast single,

axial, sometimes with angular projections with a large central pyrenoid, it may be

rounded or rod-shaped elongate; nucleus lie in the middle of the cell; cell wall bi-

layered, smooth.

Key to the taxa investigated:

1. Cells broadly oval or sub-spherical, stout, up to 2 times longer than broad

……………………...……(4) Cy. crassa

1. Cells cylindrical, elongate, above 2 times longer than broad

2. Cells small, up to 30 µm in length…….………..…(3) Cy. brebissonii var. minor

2. Cells relatively larger, above 30 µm in length

3. Chloroplast show several longitudinal bands, filling almost entire part of the

cell.......................................................................(2) Cy. brebissonii var. jenneri

3. Chloroplast not showing any such band, only having radiating prolongations,

not filling the entire cell………….…….…..(1) Cy. brebissonii var. brebissonii

1. Cylindrocystis brebisonii Meneghini var. brebisonii

(West & GS West 1904, p. 58, pl. 4, f. 23-32, pl. 5, f. 10; Krieger 1937, p. 207, pl.

6, f. 4-7; Prescott et al. 1972, p. 20, pl. 2, f. 1-5; Lenzenweger 2003, p. 32, pl. 9, f.

3-6)

[Pl. I, f. 4, 5]

Cells medium sized, 2-3 times longer than broad, cylindrical; apex broadly

rounded; lateral walls straight, parallel; chloroplast axial, pyrenoid central and

large, one in each semicells; cell wall smooth.

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Length: 46-48 µm, Breadth: 17-19 µm.

Collection No. DD-112, 18.04.2009, Khechiperi Lake, Sikkim. In association

with slimy mass growing benthic near the margins of the drain beside the Lake

(pH 6, temp. 17°C).

Indian distribution: Upper Batong Valley, Sikkim (Dickie 1882); East India

(Turner 1892); Simla (Kamat 1968); Kashmir (Suxena & Venkateswarlu 1968b);

Kodaikanal, Tamilnadu (Bharati & Pai 1972); Madhya Pradesh (Agarkar &

Agarkar 1977); Kerala (Shaji et al. 1988); Karnataka (Hegde & Isaacs 1986);

Kalimpong (Santra & Pal 2006).

2. Cylindrocystis brebisonii Meneghini var. jenneri (Ralfs) Reinsch

(Krieger 1937, p. 210, pl. 6, f. 12, 13; Prescott et al. 1972, p. 21, pl. 2, f. 6-8;

Lenzenweger 2003, p. 33, pl. 9, f. 11,12)

[Pl. I, f. 8, 9]

Cells cylindrical, 2.5-3 times longer than broad, apices broadly rounded;

chloroplast axial showing several vertical bands; cell wall smooth.

Length: 71-72 µm. Breadth: 25-26 µm.

The chloroplast shows vertical bands. These forms appear intergrading between

Cylindrocystis & Penium.

Collection No. DD-405, 06.11.2009, Changu Lake, Sikkim. In association with

dark green filamentous growing on the surface of water (pH 6, temp. 9ºC).

Indian distribution: This is probably the first report of the taxon from India.

3. Cylindrocystis brebisonii Meneghini var. minor West et GS West

(West & GS West 1904, p. 59, pl. 5, f. 11; Krieger 1937, p. 209, pl. 6, f. 8,9;

Prescott et al. 1972, p. 21, pl. 2, f. 9-12; Lenzenweger 2003, p. 33, pl. 9, f. 7-9)

[Pl. I, f. 6, 7]

Cells small, 2-3 times longer than broad, cylindrical, narrow; apices broadly

rounded; chloroplast axial, pyrenoid single in each semicell; cell wall smooth.

Length: 28-42 µm, Breadth: 12-16 µm.

No. DD-414, 06.11.2009, Mamencho Lake, Sikkim. In association with green

filamentous mass attached to the surface of the submerged aquatic plants (pH 6,

temp. 10ºC).

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Indian distribution: Kerala (Shaji et al. 1988).

This is the first report of the taxon from Eastern Himalaya.

4. Cylindrocystis crassa de Bary var. crassa

(West & GS West 1904, p. 59, pl. 4, f, 33-38; Krieger 1937, p. 211, pl. 6, f. 16,

17; Prescott et al. 1972, p. 22, pl. 2, f. 24-26; Lenzenweger 2003, p. 34, pl. 9, f.

10, 13, 14)

[Pl. I, f. 3]

Cells elliptic, about 2 times longer than broad, the poles broadly rounded;

chloroplast having numerous radiating plates and with a central pyrenoid.

Length: 82-86 µm. Breadth: 40-42 µm.

No. DD-287, 12.05.2009. Backthong falls, Sikkim. With the phytoplankton

samples collected from the falls (pH 6.5, temp. 15ºC); DD-757, Lava, West

Bengal. In association with wet mosses growing on the surface of the soil (pH 6,

temp. 16ºC).

Indian distribution: East India (Turner 1892); Kodaikanal, Tamil Nadu (Bharati

& Pai 1972) Savandurga, Karnataka (Gurudeva et al. 1983); Gangtok, Sikkim

(Prasad & Misra 1987); Rohilkhand, Uttar Pradesh (Habib 1993); Pilibhit, Uttar

Pradesh (Habib 1997).

III. Mesotaenium Nageli

Cells solitary, sometimes several aggregated within common gelatinous matrix or

paired immediately after cell division. Cells cylindrical, sub-cylindrical or elliptical,

elliptic-oval, straight or slightly curved, rarely asymmetrical, slightly attenuated to the

apex, apex rounded or sub-truncate. Chloroplast single, rarely 2, axial rarely parietal,

sometimes curved, flattened and plate-like with 1-2 pyrenoids.

Key to the taxa investigated:

1. Cells cylindrical, elongate, sub-cylindrical

2. Cells symmetrical, straight

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3. Relatively larger in dimension 13-15 µm broad, 33-36 µm long, lateral wall

convex in the midregion, apex acutely rounded

..(4) M. macrococcum var. macrococcum

3. Cells smaller 7-16 µm. broad, 16-30 µm. long, lateral walls straight, apex

broadly rounded……………………….......…(5) M. macrococcum var. minus

2. Cells asymmetrical, more diameter at one end, slightly curved

…………………(3) M. degryi var. breve

1. Cells broadly oval or elliptic, relatively short

4. Cell sap violet in colour, chloroplast covers the entire area of the cell

...(2) M. chlamydosporum var. violascens

4. Cell sap not violet in colour, chloroplast not covering the entire space of the cell

...(1) M. chlamydosporum var. chlamydosporum

1. Mesotaenium chlamydosporum de Bary var. chlamydosporum

(West & GS West 1904, p. 52, pl. 4, f. 4-14; Krieger 1937, p. 200, pl. 4, f. 1-9;

Prescott et al. 1972, p. 8, pl. 1, f. 32, 33; Lenzenweger 2003, p. 30, pl. 8, f. 1-4)

[Pl. I, f. 18, 19]

Cells oblong cylindrical, the poles broadly rounded, with small apical nodules,

1.4-1.6 times longer than broad; chloroplast parietal plate; cell wall smooth.

Length: 24-25 µm, Breadth: 16-17 µm.

Collection No. DD-379, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with deep green filamentous mass floating freely on the surface of water forming

bloom (pH 6, temp. 10ºC).

Indian distribution: East India (Turner 1892); West Bengal (Mallick 2010).

This is the first report of the taxon from Eastern Himalaya.

2. Mesotaenium chlamydosporum de Bary var. violascens (de Bary) Krieger

(Krieger 1937, p. 201, pl. 4, f. 10-11; Prescott et al. 1972, p. 9, pl. 1, f. 37-38)

[Pl. I, f. 13, 14, 16, 17]

Cells elliptic, short, 1.2-1.5 times longer than broad, chloroplast a parietal plate;

cell wall smooth; cell sap violet in colour.

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Length: 22-31 µm, Breadth: 15-22 µm.

Collection No. DD-379, 06.11.2009, Bitang-cho Lake. Sikkim. In association

with Deep green filamentous mass floating freely on the surface of water forming

bloom (pH 6, temp. 10ºC); DD-156, 19.04.2009, Kothak Lake, Sikkim. With the

phytoplankton samples collected from the Lake (pH 4.5, temp. 19ºC).

Indian distribution: This is probably the first report of the taxon from India.

3. Mesotaenium degreyii Turner var. breve West

(West & GS West 1904, p. 50, pl. 3, f. 20; Krieger 1937, p. 192, pl. 3, f. 2;

Prescott et al. 1972, p. 9, pl. 1, f. 4, 5)

[Pl. I, f. 12]

Cells cylindrical-oval in shape, stout, short, 2-2.5 times longer than broad; apices

broadly rounded; chloroplast parietal; cell wall smooth.

Length: 46-48 µm, Breadth: 20-21 µm.

Collection No. DD-160, 19.04.2009, Kothak Lake, Sikkim. Growing on the mud

on the bank of the Lake (pH 4.5, temp. 19ºC).

Indian distribution: West Bengal (Mallick 2010).

This is the first report of the taxon from Eastern Himalaya.

4. Mesotaenium macrococcum (Kützing) Roy et Bissett var. macrococcum

(West & GS West 1904, p. 51, pl. 3, f. 34-36; Krieger 1937, p. 198, pl. 4, f. 1-3;

Prescott et al. 1972, p. 11, pl. 1, f. 27-30; Lenzenweger 2003, p. 31, pl. 8, f. 11-14)

[Pl. I, f. 10, 11]

Cells medium sized, cylindrical, 2.4-2.6 times longer than broad; lateral walls

parallel and straight; poles truncately rounded; cell wall finely punctate.

Length: 33-36 µm, Breadth: 13-15 µm.

Collection No. DD-24, 16.04.2009, Pelling, Sikkim. In association with dark

green to brownish green filament forming mat (pH 5.5, temp. 21ºC); DD-412,

06.11.2009, Mamencho Lake, Sikkim. In association with dark greenish filament

floating freely on the surface of water (pH 6, temp. 10ºC).

Indian distribution: Marathwada, Maharashtra (Asthekar & Kamat 1979);

Kashmir (Compère 1983); West Bengal (Mallick 2010).

This is the first report of the taxon from Eastern Himalaya.

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5. Mesotaenium macrococcum (Kützing) Roy et Bissett var. minus (de Bary)

Compére

(Prescott et al. 1972, p. 11, pl. 1, f. 31; Lenzenweger 2003, pl. 8, f. 16, 17)

[Pl. I, f. 15, 20]

Cells cylindrical, short, 1.5-2.5 times longer than broad; lateral walls parallel,

slightly attenuated at the apices; apex broadly rounded; chloroplast axial, nearly

filling the cells; cell wall punctate.

Length: 16-30 µm, Breadth: 7-16 µm.

Collection No. DD-590, Namchi, Sikkim. In association with light green

filaments on the surface of a small water body (pH 6.5, temp. 15ºC); DD-714,

01.05.2010, Delo reservoir, Kalimpong. With phytoplankton samples collected

from the reservoir.

Indian distribution: This is probably the first report of the taxon from India.

IV. Netrium (Nageli) Itzigsohn et Rothe emend Lutkemuller

Cells solitary, elongate-cylindrical, elliptic, elliptic-fusiform, straight, rarely slightly

curved in with broadly rounded or truncate ends. Median constriction lacking. Lateral

walls generally convex, sometimes straight. Chloroplast axial with 6-12 longitudinal

ridges having smoothed, notched or serrated outer free margins; pyrenoids single to

several, rounded or elongate arranged in longitudinal series or scattered. Cell wall bi-

layered and smooth.

Key to the taxa investigated:

1. Semicells cylindrical

2. Cells elongate-cylindrical, apex broadly rounded

3. Cells rather shorter in size, cell wall smooth...…(5) N. interruptum var. minor

3. Cells relatively larger, cell wall closely punctate

………….(6) N. interruptum var. sectum

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2. Cells short, oblong-cylindrical, apex truncate-rounded

4. Cells with lateral margins straight throughout, not attenuated at the apex, apex

flat, angles rounded......................................(10) N. oblongum var. cylindricum

4. Cells with lateral margins slightly convex, attenuated to the poles, apex

truncately rounded

5. Cells oblong-cylindrical, apex truncately rounded

............(9) N. oblongum var. acuminatum

5. Cells elongate-fusiform, apex broadly rounded

................(8) N. oblongum var. oblongum

1. Cells elliptic-fusiform

6. Cells minute, about 60 µm long, elliptic, apex narrow, bluntly rounded

……………………………..(7) N. minus

6. Cells relatively larger, more than 100 µm. in length, fusiform, spindle-shaped

7. Lateral walls convex strongly

8. Cells broadly fusiform, about 2 times longer than broad

……………..…(1) N. digitus var. digitus

8. Cells relatively elongate-fusifom, more than 2 times longer than broad

.........................(2) N. digitus var. curtum

7. Lateral walls not strongly convex

9. Cells slightly longer, 3-4 times longer than broad

………………(3) N. digitus var. naegelii

9. Cells relatively short, 2-3 times longer than broad

………………..(2) N. digitus var. rectum

1. Netrium digitus (Ehrenberg) Itzigson et Rothe var. digitus

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(West & GS West 1904, p. 64, pl. 6, f. 14-16; Krieger 1937, p. 214, pl. 7, f. 1, pl.

8, f. 1; Prescott et al. 1972, p. 24, pl. 4, f. 14-16, 21; Lenzenweger 2003, p. 35, pl,

11, f. 1-4)

[Pl. II, f. 35]

Cells broadly fusiform with much convex lateral margins, gradually attenuated

from the middle to broad rounded-truncated poles; about 2 times longer than

broad; chloroplast one in each semicells with several pyrenoids; cell wall smooth.

Length: 210-213 µm, Breadth: 106-109 µm, Apex: 32-36 µm.

In present specimen the chloroplast is definitely not stellate, margin serrate and

pyrenoids in row, although chloroplast is bit distorted, many features makes it

close to N. digitus.

Collection No. DD-420, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with light green filaments on the surface ofthe water (pH 6, temp. 10ºC). DD-728,

02.05.2010, Mach pokhri, West Bengal. With phytoplankton sample collected

from the waterbody (pH 6.5, temp. 22ºC).

Indian distribution: Kodaikanal, Tamilnadu (Iyengar & Vimla Bai 1941; Singh

& Balasingh 2011); Gwalior, Madhya Pradesh (Agarkar 1969); Kodaikanal,

(Bharati & Pai 1972); Karnataka and Goa (Bharti & Hegde 1982); Savandurga,

Karnataka (Gurudeva 1983); Rohilkhand, Uttar Pradesh (Habib 1993); Pilibhit,

Uttar Pradesh (Habib 1997); Shillong, Meghalaya (Gupta 2002); Sikkim (Kumar

& Rai 2005; Santra & Pal 2006); West Bengal (Mallik 2009); Kerala (John &

Francis 2010); Eastern Himalaya (Yasmin et al. 2011); Goalpara, Assam (Deca et

al. 2011).

This is a fairly common taxon of Netrium occurring in India.

2. Netrium digitus (Ehrenberg) Itzigson et Rothe var. curtum (Borge) Krieger

(Prescott et al. 1972, p. 25, pl. 4, f. 25; Lenzenweger 2003, p. 35, pl. 11, f. 7)

[Pl. I, f. 33]

Cells broadly fusiform with strongly convex sides, gradually becoming conical

toward the truncated poles; cells 2-2.5 times longer than broad; chloroplast single

in each semicells with several pyrenoids; cell wall smooth.

Length: 103-106 µm, Breadth: 42-44 µm, Apex: 12-15 µm.

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Collection No. DD-423, Backthong falls, Sikkim. In association with dark scum

with mosses on the surface of the wet rock (pH 6, temp. 14ºC).

Indian distribution: Kumta, N. Kanara (Bharati 1965b).

This is the first report of the taxon from Eastern Himalaya.

3. Netrium digitus (Ehrenberg) Itzigson et Rothe var. naegelii (Brébisson) Krieger

(West & GS West 1904, p. 66, pl. 7, f. 4, 5 as N. naegelii (Brébisson) West et GS

West; Prescott et al. 1972, p. 26, pl. 5, f. 3, 4; Lenzenweger 2003, p. 36, pl. 11, f.

5)

[Pl. II, f. 34]

Cells oblong elongate with convex margins attenuated at the end forming

truncately rounded poles; cells 3.5-4 times longer than broad; chloroplast single in

each semicells with 6 longitudinal radiating plates having several pyrenoids; cell

wall smooth.

Length: 176-182 µm, Breadth: 45-48 µm, Apex: 17-22 µm.

Collection No. DD-756, 10.11.2011, Lava West Bengal. In association with green

filaments floats freely on the surface of a small water body (pH 6, temp. 17ºC).

Indian distribution: Kerala (Shaji et al. 1988).

This is the first report of the taxon from Eastern Himalaya.

4. Netrium digitus (Ehrenberg) Itzigson et Rothe var. rectum (Turner) Krieger

(Krieger 1937, p. 216, pl. 7, f. 2; Prescott et al. 1972, p. 26, pl. 4, f. 22)

[Pl. II, f. 36]

Cells oblong elliptic, broad with convex margins, the end somewhat produced and

gradually tapering forming truncated poles; chloroplast single in each semicells

having radiating ridges with elongate pyrenoids; cell wall smooth.

Length: 164-167 µm, Breadth: 54-57 µm, Apex: 14-15 µm.

Collection No. DD-500, 09.11.2009, Change falls, Sikkim. As brownish scum on

the surface of the water under the flowing water (pH 6, temp. 14ºC).

Indian distribution: West Bengal (Mallik 2009).

This is the first report of the taxon from Eastern Himalaya.

5. Netrium interruptum (Brébisson) Lütkemüller var. minor (Borge) Krieger

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(Prescott et al. 1972, p. 28, pl. 5, f. 19; Krieger 1937, p. 223, pl. 8, f. 10;

Lenzenweger 2003, pl. 11, f. 16)

[Pl. II, f. 38]

Cells small, cylindrical, 4-6 times longer than broad; apices obtusely rounded;

wall smooth; chloroplast median and cylindrical, 2 in each semicell with a central

pyrenoid, each chloroplast having about 8 longitudinal ridges, the margins of

which are entire.

Length: 68-74 µm, Breadth: 12-15 µm, Apex: 7-9 µm.

Collection No. DD-415, 06.11.2009, Mamencho Lake, Sikkim. In association

with greenish-brown scum attached to the surface of the wet rock (pH 6, temp.

10ºC).

Indian distribution: Mamencho Lake, Sikkim (Das & Keshri 2012).

6. Netrium interruptum (Brébisson) Lütkemüller var. sectum West et GS West

(West & GS West 1904, p. 69, pl. 7, f. 3; Krieger 1937, p. 223, pl. 8, f. 9; Prescott

et al. 1972, p. 28, pl. 5, f. 20)

[Pl. II, f. 39, 40]

Cells cylindrical, margins parallel forming rounded poles at the apices; 5-5.5

times longer than broad; chloroplast 2 in each semicells, each with about 8-10

longitudinal ridges, the margins of which are entire; cell wall finely punctate.

Length: 95-100 µm, Breadth: 18-20 µm, Apex: 16-17 µm.

Collection No. DD-190, 19.04.2009, Yoksum, Sikkim. In association with

brownish filamentous scum in stagnant water under a small water falls (pH 4.5,

temp. 18ºC).

Indian distribution: This is probably the first report of the taxon from India.

7. Netrium minus Prescott

(Prescott et al. 1972, p. 28, pl. 5, f. 9)

[Pl. II, f. 46]

Cells small, lanceolate, lateral walls convex, gradually attenuated at the apices

forming bluntly truncated poles; cells 4.5-5 times longer than broad; chloroplast

axial, single in each semicells, with about 4 longitudinal ridges and a central

pyrenoid; cell wall smooth.

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Length: 60-62 µm, Breadth: 12-13 µm, Apex: 2-3 µm.

Present specimen is close to N. minus Prescott however, it differs from it in

1. Being longer

2. Less broader.

Collection No. DD-391, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with Brownish scum attached to the surface of the submerged part of the semi-

aquatic plants (pH 6, temp. 10ºC).

Indian distribution: This is probably the first report of the taxon from India.

8. Netrium oblongum (de Bary) Lütkemüller var. oblongum

(West & GS West 1904, p. 66, pl. 8, f. 1-3; Krieger 1937, p. 220, pl. 8, f. 6;

Prescott et al. 1972, p. 29, pl. 5, f. 14 Lenzenweger 2003, p. 37, pl. 11, f. 11-13)

[Pl. II, f. 37]

Cells oblong cylindrical, margins convex, gradually narrowed toward the rounded

poles; cells 2.5-3 times longer than broad; chloroplast single in each semicells

with having 3 pyrenoids; cell wall smooth.

Length: 132-134 µm, Breadth: 45-48 µm, Apex: µm.

Collection No. DD-124, 18.04.2009, Khechiperi Lake, Sikkim. As scum in

association with the members of Iridaceae (pH 5, temp. 19ºC); DD-778, Lolegaon,

West Bengal. In association with blueish green scum on the surface of the grasses.

Indian distribution: This is probably the first report of the taxon from India.

9. Netrium oblongum (de Bary) Lütkemüller var. acuminatum Irénée-Marie

(Prescott et al. 1972, p. 29, pl. 5, f. 13)

[pl. II, f. 43-45]

Cells medium sized, elongate fusiform, 2.5-4 times longer than broad; lateral

margins convex, gradually narrowed toward the broadly rounded poles, but with a

slight retuse near the apices, the poles broadly rounded; chloroplast single in each

semicells with several pyrenoids; cell wall smooth.

Length: 77-168 µm, Breadth: 20-57 µm, Apex: 10-16 µm.

Collection No. DD-417, 06.11.2009 Mamencho, Lake. Sikkim In association with

g reenish-brown scum on the surface of the wet rock (pH 6, temp. 10ºC); DD-422,

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06.11.2009 Backthong falls, Sikkim. In association with brownish scum with

mosses on the wet surface of rock (pH 6, temp. 14ºC).

Indian distribution: This is probably the first report of the taxon from India.

10. Netrium oblongum (de Bary) Lütkemüller var. cylindricum West et GS West

(West & GS West 1904, p. 67, pl. 5, f. 7; Prescott et al. 1972, p. 30, pl. 5, f. 15)

[Pl. II, f. 41, 42]

Cells decidedly cylindrical with broadly rounded poles, lateral margins parallel, 3-

3.5 times longer than broad; chloroplast 2 in each semicells having 6 longitudinal

ridges with serrate margins, pyrenoid single in each chloroplast; cell wall smooth.

Length: 64-69 µm, Breadth: 20-23 µm.

Collection No. DD-405, 06.11.2009 Changu Lake, Sikkim. In association with

dark green filaments on the surface of the water (pH 6, temp. 9ºC).

Indian distribution: This is probably the first report of the taxon from India.

V. Roya West et GS West

Cells solitary, elongate, cylindrical or sub-cylindrical, slightly curved or bow-shaped

with broadly rounded or truncate ends; chloroplast axial, ribbon-shaped band or plate

with a row of up to 10 pyrenoids or more. A median notch is present in the

chloroplast. Cell wall smooth, colourless, without pores, bi-layered, a polar vacuole is

present in some species.

Key to the taxa investigated:

1. Cells slightly attenuated toward the apices, poles broadly rounded

........................(1) R. obtusa var. obtusa

1. Cells with lateral walls parallel, poles angularly truncated

……………...(2) R. obtusa var. montana

1. Roya obtusa (Brébisson) West et GS West var. obtusa

(West & GS West 1904, p. 106, pl. 10, f. 27; Krieger 1937, p. 204, pl. 5, f. 4;

Prescott et al. 1972, p. 31, pl.6, f. 1-8; Lenzenweger 2003, p. 28, pl. 8, f. 18, 19)

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[Pl. I, f. 25, 26]

Cells cylindrical, slightly curved, 4-5 times longer than broad, somewhat

attenuated toward the apices; apex broadly and obtusely rounded; chloroplast

extended the entire portion of the cell with a slight notch at the midregion,

pyrenoids several; cell wall finely punctate

Length: 54-57 µm, Breadth: 12-13 µm.

Collection No. DD-380, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with green filaments growing attached on pebbles & submerged weeds (pH 6,

temp. 10ºC).

Indian distribution: This is probably the first report of this taxon from India.

2. Roya obtusa (Brébisson) West et GS West var. montana West et GS West

(West & GS West 1904, p. 108, pl. 10, f. 28, 29; Krieger 1937, p. 204, pl. 5, f. 5,

6; Prescott et al. 1972, p. 32, pl.6, f. 9-12; Lenzenweger 2003, p. 29, pl. 8, f. 20,

21)

[Pl. I, f. 27, 28]

Cells cylindrical, elongate, straight, 5-6 times longer than broad; lateral walls

parallel, apex angularly truncated; chloroplast axial, notch at the midregion is

prominent; 6 pyrenoids in a series; cell wall smooth.

Length: 70-73 µm, Breadth: 12-13 µm.

Collection No. DD-380, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with green filaments growing attached on pebbles & submerged weeds (pH 6,

temp. 10ºC).

Indian distribution: This is probably the first report of this taxon from India.

VI. Spirotaenia Brébisson

Cells solitary, sometimes in pairs and enclosed by a common mucilaginous mass,

small to medium sized, cylindrical, oblong-cylindrical, elliptic or fusiform, straight,

sometimes slightly lunate, with broadly rounded apex, apex sometimes acutely

pointed. Chloroplast parietal, spirally coiled band, extending end to end, pyrenoids

several. Cell wall smooth and colourless.

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1. Spirotaenia condensata Brébisson

(West & GS West 1904, p. 38, pl. 2, f. 7-10; Krieger 1937, p. 181, pl. 2, f. 1;

Prescott et al. 1972, p. 15, pl. 3, f. 18-21; Lenzenweger 2003, p. 26, pl. 10, f. 5-7)

[Pl. I, f. 29-32]

Cells cylindrical with broadly rounded poles, 4-8 times longer than broad; lateral

walls slightly convex, nearly parallel, wall smooth; chloroplast a broad parietal

ribbon making 7 close turns.

Length: 88-136 µm, Breadth: 17-22 µm, Apex: 5-6 µm.

Collection No. DD-489, 09.11.2009, Khechiperi Lake, Sikkim. In association

with other phytoplanktons of squished water from Sphagnum growing on the

banks of the Lake (pH 6, temp. 14°C); DD-833, 12.11.2011, Lava, West Bengal.

In association with blackish filamentous mass on decayed plant.

Indian distribution: Khan River, Indore (Rao et al. 1981); West Bengal

(Mukherjee & Srivastava 1993); Sattar, Tamil Nadu (Rajagopal et al. 2010);

Kerala (John & Francis 2010).

This is the first report of the taxon from Eastern Himalaya.

VII. Tortitaenia (Ralfs) Brook

Cells solitary, oblong-cylindrical, elliptic or fusiform, straight with apex rounded or

sub-acute. Cells sometimes lie in mucilaginous sheath. Chloropalst axial, consisting

of a core of several spirally coiled ridges like a ‘screw’.

Key to the taxa investigated:

1. Cells smaller in dimension, up to 70 µm in length, chloroplast having 3 turns

..............................................(1) T. alpina

1. Cells of larger dimension, more than 100 µm length, chloroplast almost straight

...........................................(2) T. obscura

1. Tortitaenia alpina (Schmidle) Brook

(John et al. 2002, p. 505, pl. 128K, f. 9, 10)

[Pl. I, f. 21]

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Cells small, sub-cylindrical, 4-5 times longer than broad; lateral margin convex at

the mid-region and tapering to a narrowly rounded poles; chloroplast axial core

making 3 turns.

Length: 58-66 µm, Breadth: 14-15 µm, Apex: 3-5 µm.

Collection No. DD-27, 16.04.2009, Chonam cho Lake, Pelling, Sikkim. With

phytoplankton samples collected from the Lake (pH 5, temp. 21ºC).

Indian distribution: This is probably the first report of this taxon from India.

2. Tortitaenia obscura (Ralfs) Brook

(Yasmin et al. 2011, p. 6, f. 4a)

[Pl. I, f. 22-24]

Cells medium sized, 5-6 times longer than broad, broadly fusiform in the

midregion, attenuated at the apices; apex rounded; chloroplast axial, not quiet

extended to the poles, cristate with 4 ridges, spirally twisted to the left, almost

straight, the ridges thickened at the free margins; pyrenoid several; cell wall

areolate.

Length: 129-164 µm, Breadth: 22-25 µm, Apex: 4-7 µm.

Collection No. DD-380, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with green scum in a swamp (pH 6, temp. 10ºC); DD-574, 10.11.2009. Uttare,

Sikkim. In association with brawn scum collected from a rock pool (pH 6, temp.

16ºC); DD-726, 02.05.2010, Mach pokhri, Kalimpong. In association with green

filaments attached on a submerged substrate (pH 6.4, temp. 24ºC).

Indian distribution: Eastern Himalaya (Yasmin et al. 2011).

Desmidiales: Placoderm desmids

(Gonatozygaceae, Peniaceae, Closteriaceae, Desmidiaceae)

Cells having cell wall consisting two pieces called semicell, adjoined in the mid

region by distinct isthmus, sometimes cells attached end to end forming pseudo-

filament, cell wall with pores and other ornamentations, sometimes smooth.

Key to the genera described:

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1. Cells attached end to end forming filament

2. Cells attached by apical granules or rod like processes

3. Cells united by apical granules…………………..………...…(XVII) Teilingia

3. Cells united by rod-like processes……………........………(XII) Onychonema

2. Cells attached by their apical wall

3. Cells cylindrical…………………………..…........……………(X) Hyalotheca

3. Cells shaped otherwise

4. Semicells transversely oval or reniform, sinus distinct...(XV) Spondylosium

4. Semicells mostly quadrangular, sinus indistinct………........(V) Desmidium

1. Cells solitary, not in filaments, rarely forming pseudofilaments

5. Cells elongate, cylindrical, straight or slightly curved or crescent shaped

6. Cells curved or crescent shaped…………………........................(III) Closterium

6. Cells straight, not curved

7. Apex of the semicells with spines

8. Cells bearing whorls of spines or tooth throughout the length

……….(XIX) Triploceras

8. Cells without whorls or tooth throughout the length…...(XVIII) Triplastrum

7. Apex of the semicells smooth, sometimes with granules

9. Cells with conspicuous median constriction

10. Semicells with one or more basal swelling………...(XIV) Pleurotaenium

10. Semicells without basal swelling…………..........................(XIII) Penium

9. Median constriction inconspicuous or absent

11. Median constriction inconspicuous, each semicells containing single

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chloroplast....................................................................(IX) Haplotaenium

11. Median constriction absent, chloroplast covering the entire cell

12. Chloroplast 2-3 spirally coiled parietal bands…........(VII) Genicularia

12. Chloroplast single, axial ribbon like………….......(VIII) Gonatozygon

5. Cells not elongate, nor cylindric, compressed and stout

13. Cells strongly compressed dorsiventrally

14. Cells disc shaped, flat with radiating lobes and sometimes with lobules

extended in one plane......................................................(XI) Micrasterias

14. Cells cup shaped or narrowly elliptic with 2 or more arms extended in

one or more plane..........................................................(XVI) Staurastrum

13. Cells not compressed dorsiventrally

15. Semicells with apical constriction..........................................(VI) Euastrum

15. Semicells without apical constriction

16. Semicells with long stout spines

17. Semicells with 2 lateral spines, not in pairs…........(II) Arthrodesmus

17. Semicells with 4-8 or more spines always in pair...(XX) Xanthidium

16. Semicells without spines, if present are minute

19. Median incision or sinus conspicuous.....................(IV) Cosmarium

19. Median incision or sinus shallow and inconspicuous

.....................................(I) Actinotaenium

I. Actinotaenium (Nägeli) Teiling

Cells solitary, elongate, sometimes short, fusiform to cylindrical with a very shallow,

faint median constriction; lateral walls parallel or tapering to the apex; apex broadly

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rounded or sometimes truncate; chloroplast single, mostly axial and stellate,

sometimes having several longitudinal ridges with single central pyrenoid (rarely 2-

3); cell wall smooth or punctate or granulate or scrobiculate.

Key to the taxa investigated:

1. Cells having sinus with a very shallow notch, sometimes not prominent

2. Cells small, shaped cylindrical

3. Cells with lateral walls parallel, apex broadly rounded

……..……(3) A. cucurbita f. rotundatum

3. Cells with lateral walls slightly tapering, apex narrowly rounded

…...….…(4) A. cucurbitinum f. minutum

2. Cells relatively larger, shaped oval

4. Cells stout, less than 2 times longer than broad, punctae with honey-comb like

ornamentation pattern……………………...…….…(8) A. sikkimicum sp. nov.

4. Cells slender, 2 times or more longer than broad, punctae arranged in vertical

series not like above…………...………………………(2) A. capax var. minus

1. Cells having well marked sinus

5. Semicells semicircular

6. Cells with greatest breadth at the lower half of the semicells, apex little

tapering…………………………………….………………(9) A. subglobosum

6. Cells with greatest breadth at the middle of the semicells, apex broadly

rounded……………………………………………..…………(7) A. globosum

5. Semicells not semicircular, rather cylindrical

7. Cells smaller in dimension, below 40 µm in length, apex sharply rounded

…...………………(5) A. curtum f. minus

7. Cells relatively larger, above 40 µm in length, apex broadly rounded

8. Cells elongate, mostly above 2 times longer than broad, sinus very shallow

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……(6) A. diplosporum var. americanum

8. Cells stout, less than 2 times longer than broad, sinus relatively deep

…………………..…….…(1) A. australe

1. Actinotaenium australe (Raciborski) Croasdale

(Prescott et al. 1981, p. 4, pl. 150, f. 14, 15)

[Pl. II, f. 47, 48]

Cells medium sized, broadly elliptic, 1.6 times longer than broad, scarcely

constricted at isthmus, very little tapered at the apex; apex broadly rounded;

chloroplast with 6 longitudinal lamellae and a large central pyrenoid; wall

punctate.

Length: 88-89 µm, Breadth: 54-55 µm, Isthmus: 45-46 µm.

Collection No: DD-379, 06.11.2009. Bitang-cho Lake, Sikkim. In association

with green filaments growing attached on pebbles & submerged weeds (pH 6,

temp. 10ºC).

Indian distribution: This is probably the first report of this taxon from India.

2. Actinotaenium capax (Joshua) Teiling var. minus (Schmidle) Teiling ex Růžička

et Pouzer

(Prescott et al. 1981, p. 6, pl. 156, f. 9)

[Pl. II, f. 49, 50]

Cells large, ovate, 2 times longer than broad; median incision very much shallow,

semicells with highest width just above the base, then tapering to the broadly

rounded apex; cell wall punctate, punctae evenly distributed in several vertical

lines except the narrow zone of isthmus which is smooth; chloroplast parietal with

4 longitudinal ridges.

Length: 109-114 µm, Breadth: 54-57 µm, Isthmus: 49-52 µm.

Our specimen is bit smaller than the type.

Collection No. DD-389, 06.11.2009. Bitang-cho Lake, Sikkim. In association

with light green filaments on the surface ofthe water (pH 6, temp. 10ºC).

Indian distribution: This is probably the first report of this taxon from India.

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3. Actinotaenium cucurbita (Brébisson) Teiling ex Růžička et Pouzer var. cucurbita

f. rotundatum (Krieger) Teiling

(Prescott et al. 1981, p. 10, pl. 152, f. 12-14)

[Pl. III, f. 61]

Cells small, 1.5-2 times longer than broad; sinus a notch; sides convex, tapering

only very slightly toward the apex; apex broadly rounded; cell wall with fine,

sparse punctae, randomly distributed, wall slightly thickened; chloroplast axial

with irregular longitudinal lamellae.

Length: 31-32 µm, Breadth: 17-19 µm, Isthmus: 16-17 µm.

Collection No: DD-124, 18.04.2009. Khechiperi Lake, Sikkim. From the water

squished from the bog pool (pH 5, temp. 19ºC).

Indian distribution: Kerala (Sindhu & Panikkar 1995a).

This is the first report of the taxon from Eastern Himalaya.

4. Actinotaenium cucurbitinum (Bisset) Teiling var. cucurbitinum f. minutum

(Teiling) Croasdale

(Prescott et al. 1981, p. 12, pl. 151, f. 6-7)

[Pl. III, f. 60]

Cells small, 2 times longer than broad; sinus a shallow notch; lateral margin

slightly tapered to rounded apex; cell wall finely and sparsely punctate;

chloroplast axial.

Length: 31-33 µm, Breadth: 16-17 µm, Isthmus: 15-16 µm.

Collection No. DD-393, 06.11.2009, Bitang-cho Lake. In association with light

green filaments growing on the surface of the water (pH 6, temp. 10ºC). DD-525,

10.11.2009, Dentam River. In association with deep green filamentous masses

floating freely on the surface of water (pH 6, temp. 19ºC).

Indian distribution: Karnataka (Isaacs & Hegde 1987).

This is the first report of the taxon from Eastern Himalaya.

5. Actinotaenium curtum (Brébisson ex Ralfs) Teiling ex Růžička et Pouzer var.

curtum f. minus (Rabenhorst) Teiling ex Croasdale

(Prescott et al. 1981, p. 14, pl. 8, f. 6)

[Pl. II, f. 56-58]

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Cells small, about 1.5-2 times longer than broad; sinus a shallow notch; sides of

semicell tapering strongly to a broadly rounded apex; chloroplast axial with

several longitudinal lamellae and a central pyrenoid; cell wall may be smooth or

finely punctate.

Length: 23-34 µm, Breadth: 14-18 µm, Isthmus: 12-15 µm.

Collection No. DD-523, 10.11.2009. Dentum River, Sikkim. In association with

green filaments on rocks under flowing water (pH 6, temp. 19ºC). DD-454,

09.11.2009. Kanchanjangha falls, Sikkim. In association with brown scum on wet

rocks in partially shady place. DD-794, 11.11.2011, Rishop, West Bengal. As

black powdery mass in association with mosses growing on tree trunk.

Indian distribution: This is probably the first report of the taxon from India.

6. Actinotaenium diplosporum (Lundel) Teiling var. americanum (West et GS

West) Teiling

(Prescott et al. 1981, p. 16, pl. 155, f. 7, 8)

[Pl. III, f. 62]

Cells medium sized, about 2 times longer than broad, elongate, guitar shaped (i.e.

greatest breadth in the middle of the semicells); sinus shallow but prominent; apex

broad, truncately rounded; chloroplast axial; cell wall evenly and coarsely

punctate.

Length: 52-55 µm, Breadth: 23-26 µm, Isthmus: 18-21 µm.

Collection No. DD-389, 06.11.2009. Bitang-cho Lake, Sikkim. In association

with light green filaments on the surface of the water (pH 6, temp. 10ºC).

Indian distribution: Madhya Pradesh (Agarkar & Agarkar 1977).

This is the first report of the taxon from Eastern Himalaya.

7. Actinotaenium globosum (Bulnheim) Förster ex Compère var. globosum f.

globosum

(Prescott et al. 1981, p. 17, pl. 150, f. 8-11; Lenzenweger 1996, p. 117, pl. 17, f. 3)

[Pl. III, f. 59]

Cells small, 1.5-2 times longer than broad; slightly but sharply constricted at the

midregion; semicells semicircular in outline; lateral margins with apex broadly

rounded; cell wall finely punctate; chloroplast axial with single central pyrenoid.

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Length: 31-32 µm, Breadth: 17-19 µm, Isthmus: 15-16 µm.

Collection No: DD-419, 6.11.2009, Mamencho Lake, Sikkim. In association with

greenish-yellow filaments on the surface of the water (pH 6, temp. 10ºC). DD-

396, 6.11.2009. Baba Mandir, Sikkim. In association with wet grass growing in a

swallow damp (pH 6.5, temp. 13ºC).

Indian distribution: Gujarat (Kamat 1962); Madhya Pradesh (Agarkar &

Agarkar 1977); Kashmir (Compère 1983).

This is the first report of the taxon from Eastern Himalaya.

8. Actinotaenium sikkimicum sp. nov.

[Pl. II, f. 51, 52]

Cells large, 1.7 times longer than broad; Sinus only a shallow notch; lateral

margins convex and attenuated to the apex forming broadly rounded poles; cell

wall punctate, 6 punctae arranged in such a manner just like honey-comb all over

the cell wall; chloroplast axial with central pyrenoid.

Length: 112-115 µm, Breadth: 65-67 µm, Isthmus: 62-64 µm.

Present taxon is quiet similar in morphology to A. capax (Joshua) Teiling but

differs in following:

1. Honey-comb like ornamentation pattern on the cell wall

2. Cell stouter, length/breadth ratio less than 2.

It differs from all other species of Actinotaenium in having Honey-comb like

ornamentation pattern on the cell wall.

Holotype No. DD-380, 06.11.2009. Bitang-cho Lake. In association with deep

green filamentous mass floating freely on the surface of water forming bloom (pH

6, temp. 10ºC). Kept in the algae herbarium, Department of Botany, The

University of Burdwan (BURD).

9. Actinotaenium subglobosum (Nordstedt) Teiling

(Prescott et al. 1981, p. 22, pl. 150, f. 16-18; Lenzenweger, 1996, p. 119, pl. 17, f.

4)

[Pl. II, f. 53, 54, pl. III, f. 55]

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Cells medium sized, 1.5-2 times longer than broad; sinus shallow notch; lateral

margins and apex broadly rounded; cell wall sparsely punctate; chloroplast

stelloid with 6 longitudinal lamellae.

Length: 36-74 µm, Breadth: 20-48 µm, Isthmus: 19-20 µm.

One specimen was recorded having larger dimension than the type

Collection No: DD-284, 12.05.2009. Backthong falls, Sikkim. In association with

liverworts growing on the wet rock. DD-583, 12.11.2009. In association with wet

mosses forming brown scum growing on the soil.

Indian distribution: Madhya Pradesh (Agarkar et al. 1979).

This is the first report of the taxon from Eastern Himalaya.

II. Arthrodesmus Ehrenberg ex Ralfs

Solitary, small to medium sized, compressed. Median constriction fairly deep, sinus

open, broad, rarely closed often broadly ‘V’-shaped. In face view semicells may be

semicircular, quadrate, elliptic, sub-elliptic or triangular rarely polygonal. In vertical

view the semicells are elliptic or oval. Semicells furnished with a pair of simple

lateral spines emerge from lateral angles. Spines short or long, stout or rarely small

minute, upwardly or downwardly directed sometimes straight parallel, horizontally

placed. Cell wall smooth or finely punctate; face of the semicells always smooth,

without any protuberance. Chloroplast axial, 1-2 in each semicell with a central

pyrenoids.

Key to the taxa investigated:

1. Semicells trapeziform or sub-trapezoid, apex flat, spines straight, upwardly

directed………………………………………………........................(4) A. extensus

1. Semicells transversely sub-elliptic, spines curved, downwardly directed

2. Sinus acute angled at the extremity, spines acicular

…...…(1) A. convergens var. convergens

2. Sinus rounded at the extremity, spines blunt

3. Spines short, cell wall smooth..........................(3) A. curvatus var. americanus

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3. Spines long, cell wall densely punctate........(2) A. convergens var. incrassatus

1. Arthrodesmus convergens Ehrenberg ex Ralfs var. convergens

(Prescott et al. 1982, p. 10, pl. 304, f. 2-4, 6, 9f, 12f)

[Pl. III, f. 63-65]

Cells medium sized, 1.1-1.3 times longer than broad without spines; median

constriction deep, the sinus widely open, acute angled with a rounded extremity;

semicells transversely sub-elliptic, the basal margins convex, the angles attenuate,

acute and furnished with a stout, rather long, slightly downwardly projected

curved spine; the apex relatively broad and convex, the contour of the apex and

the spines forming an arch; cell wall smooth.

Length: 39-45 µm, Breadth: 55-58 µm (with spines), 38-43 µm (without spines),

Isthmus: 9-23 µm.

Collection No. DD-125, DD-133, 18.04.2009, Khechiperi Lake, Sikkim. In

association with brownish wooly masses growing in water. (pH 5.5, temp. 17°C).

DD-420, 06.11.2009, Mamencho Lake Sikkim. In association with brownish

wooly masses growing in water. (pH 5.5, temp. 10°C).

Indian distribution: Eastern India (Turner 1892); Karnataka (Bharati, 1965);

Bombay & Karnataka (Bharati 1966); Ranchi, Bihar (Sinha & Mishra 1967);

Andhra Pradesh (Suxena & Venkateswarlu 1970); Gwalior, Madhya Pradesh

(Agarkar 1971); Kodaikanal, (Bharati & Pai 1972); Vidarbh, Maharashtra (Kamat

1975); Udalkachar, Madhya Pradesh (Habib 1991); Rohilakhand, Uttar Pradesh

(Habib 1993); West Bengal (Mukherjee & Srivastava 1993); Uttar Pradesh (Misra

& Srivastava 2003); Uttarakhand (Misra et al. 2008); Sitapur, Uttar Pradesh

(Habib 2008); Hardoi, Uttar Pradesh (Habib 2009); Dehradun, Uttarakhand

(Habib & Chaturvedi 2012).

This is the first report of the taxon from Eastern Himalaya.

2. Arthrodesmus convergens Ehrenberg ex Ralfs var. incrassatus Gutwinski

(Prescott et al. 1982, p. 11, pl. 303, f. 5, 7, 11)

[Pl. III, f. 68, 69]

Cells medium sized, slightly longer than broad without spines; median

constriction deep, sinus widely open with rounded extremities; semicells

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transversely sub-elliptic, somewhat depressed; apex truncately rounded; angles

furnished with a long, blunt simple, curved spine downwardly directed; basal

margins broadly convex; cell wall densely punctate; semicells with single

chloroplast.

Length: 30-33 µm, Breadth: 55-58 µm (with spines), 29-32 µm (without spines),

Isthmus: 5-7 µm.

Collection No. DD-411, 06.11.2009 Mamencho Lake, Sikkim. In association with

light green filaments swims freely on the surface of the water. (pH 6, Temp.

10°C).

Indian distribution: This is probably the first report of the taxon from India.

3. Arthrodesmus curvatus Turner var. americanus Scott et Gronblad

(Prescott et al. 1982, p. 13, pl. 307, f. 4, 6, 7; pl. 308, f. 5, 7, 8)

[Pl. III, f. 70-73]

Cells medium sized, about 1.3 times longer than broad without spines; median

constriction deep, sinus wide open with rounded extremities; semicells

transversely elliptic; lateral angles furnished with a simple, long, blunt, curved

stout spine which is downwardly directed; basal margins slightly convex; cell wall

smooth; in vertical view cell elliptic with ends furnished with single long spine;

chloroplast 2 in each semicells.

Length: 28-29 µm, Breadth: 37-40 µm (with spines), 25-28 µm (without spines),

Isthmus: 8-11 µm.

Collection No. DD-410, 06.11.2009, Mamencho Lake, Sikkim. In association

with deep green filaments floating freely on the surface of the water. (pH 6, Temp.

10°C).

Indian distribution: This is probably the first report of the taxon from India.

4. Arthrodesmus extensus (Borge) Hirano var. extensus

(Prescott et al. 1982, p. 15, pl. 299, f. 3, 7, 8, 13-15, 20)

[Pl. III, f. 66, 67]

Cells small, 1.4-1.5 times broader than long, median constriction deep, the sinus

widely open, sub-semicircular; isthmus somewhat elongate; semicells sub-

trapeziform, the lower, lateral margin straight, the basal angle obtusely rounded,

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the upper, lateral margin straight and diverging upwards, the upper angles sharper,

acute angled and furnished with a simple, long, straight, divergent spine; the apex

broad, flat; cell wall smooth.

Length: 35-36 µm (with spine) 22-23 µm (without spine), Breadth: 51-52 µm

(with spine) 25-26 µm (without spine), Isthmus: 7-9 µm.

Collection No. DD-410, 06.11.2009, Mamencho Lake, Sikkim. In association

with deep green filaments floating freely on the surface of the water (pH 6, temp.

10°C).

Indian distribution: This is probably the first report of the taxon from India.

III. Closterium Nitzsch ex Ralfs

Cells solitary, elongate-cylindrical to elongate-fusiform, lunate, crescent-shaped or

sometimes straight, needle shaped, attenuated from the midregion to broad, truncate

or rounded, narrowly pointed or bluntly to sharply acute or rounded apices, rarely

apex may enlarged, knob-like thick or button-like, some species with apical extension

extended into rostrate or seta-like projections, sometimes apex may be incurved or

recurved; midregion may be tumid for variable length, ventral margin may be convex,

straight, or convex for its entire length; cell wall smooth, striated, costate or punctate,

there are several pattern of these ornamentations; cell wall may be yellowish or

brownish but mostly colourless; in some species one or more girdle bands present on

the midregion or just away from the midregion; chloroplast two, one in each

semicells, rarely four, axial plate or with several longitudinal ridges; pyrenoids few to

many, usually in single series or sometimes scatteredly arranged throughout the

chloroplast; single nucleus in the midregion between the two chloroplast; often with

terminal vacuoles having several vibrating granules.

Key to the taxa investigated:

1. Cells without a girdle band

2. Cells straight, sometimes little curved only for the small apical portion

3. Apex broad or swollen

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4. Apex swollen, button like….……...………...(32) Cl. mamenchoenum sp. nov.

4. Apex flat or rounded, not swollen

5. Both the margins equally curved

6. Apex truncate, cell wall smooth

7. Cells small, not more than 130 µm

8. Cell broad, fusiform, midregion inflated……………..(36) Cl. navicula

8. Cells slightly longer, midregion not inflated

9. Apex broadly rounded, terminal vacuoles with vibrating granules

.………….(26) Cl. libellula var. libellula

9. Apex flat, terminal vacuoles not having granules

……....(27) Cl. libellula var. intermidium

7. Cell dimension large, more than 400 µm….......(46) Cl. rectimarginatum

6. Apex flat with rounded angles, cell wall striated

…………….(48) Cl. reticulatum sp. nov.

5. Dorsal margin more curved than the ventral, ventral wall straight or very

slightly curved

10. Ventral margin very slightly concave, apex broadly rounded

…………………...(45) Cl. pseudolunula

10. Ventral margin distinctly convex, apex sharply rounded or flat

11. Cells larger, apex flat……………..(31) Cl. lunula var. lunula f. minor

11. Cells smaller, apex sharply or acutely rounded

…….(30) Cl. lunula var. lunula f. lunula

3. Apex not broad or swollen, rather pointed

12. Cells narrow, long and slender

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13. Certain part of the cells apex recurved

14. Cells longer, above 100 µm long...………….(20) Cl. gracile var. gracile

14. Cells smaller in length, less than 100 µm long

………………(21) Cl. gracile var. tenue

13. Cells straight for its all part, apex not recurved

15. Apex acutely pointed, cell smaller in length, below 100 µm. long

……………………......….(4) Cl. acutum

15. Apex acutely rounded, cell larger, above 100 µm. long

……...…(7) Cl. bitangchoianum sp. nov.

12. Cells less slender, inflated in the midregion

16. Cells recurved in the apical region

17. Cells longer, about ¼ portion of the midregion inflated, apical extension

long, cell wall striated…………………………….……(51) Cl. setaceum

17. Cells relatively small, ¾ portion of the midregion inflated, apical

extension short, cell wall smooth……………..……….(49) Cl. rostratum

16. Cells not recurved in the apical region

18. Isthmus region pointed

19. Apex with invagination, chloroplast not ridged

....(29) Cl. littorale var. indicum var. nov.

19. Apex not invaginate, chloroplast ridged

.....(28) Cl. libellula var. sikkimense var nov.

18. Isthmus region not pointed

20. Apex narrow-blunt, cell wall colourless, pyrenoids 5-7

……………………(57) Cl. subfusiforme

20. Apex narrow-rounded, broader, cell wall yellowish in colour,

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pyrenoids many, 9-11 in number….......(47) Cl. rectimarginatum forma

2. Cells curved, bow-shaped to crescent-shaped

21. Apex truncate, broadly or sharply rounded

22. Apex truncate or broadly rounded

23. Apex truncate…..…………….……...…..…(3) Cl. acerosum var. tumidum

23. Poles broadly rounded

24. Midregion definitely tumid and pointed

….(16) Cl. ehrenbergii var. ehrenbergii forma

24. Midregion less tumid

25. Apex more curved

26. Cell dimension small, less than 100 µm long

……………....(14) Cl. eborascens forma

26. Cells relatively large, length more than 250 µm long

……………..……….(13) Cl. eborascens

25. Apex not curved

27. Pyrenoids 3-4 arranged in series

….(34) Cl. moniliferum var. moniliferum

27. Pyrenoids 7-9 in series, scatteredly arranged

….(35) Cl. moniliferum var. submoniliferum

22. Apex not broad, sharply rounded

28. Midregion tumid

29. Cell wall definitely striated…..(17) Cl. ehrenbergii var. malinvernianum

29. Cell wall smooth……………..…….(15) Cl. ehrenbergii var. ehrenbergii

28. Midregion straight or convex

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30. Ventral wall convex, cells small, 50-60 µm. long

....(33) Cl. minutum var. indicum sp. nov.

30. Ventral wall straight, cells large 400-450 µm. long

…….(18) Cl. ehrenbergii var. podolicum

21. Apex narrow, acute, sharply or narrowly rounded

31. Cells larger, more than 100 µm. in length

32. Midregion slightly tumid

33. Cells strongly curved, curvature 140º-160º

34. Ventral wall less tumid, apex rounded…….(61) Cl. tumidulum forma

34. Ventral wall distinctly tumid, apex narrow………(60) Cl. tumidulum

33. Cells less curved

35. Apex pointed, cell wall redish-yellow

…….…(5) Cl. arcuarium var. arcuarium

35. Apex blunt, cell wall not yellowish

….(6) Cl. arcuarium var. sikkimense var. nov.

32. Midregion not tumid

36. Cell less curved, curvature less than 110º

37. Poles not oblique, sharply rounded..…..….(38) Cl. parvulum forma

37. Poles obliquely rounded, pointed

38. Dorsal wall more curved than the ventral

………………(12) Cl. dianae var. minor

38. Both walls are similarly curved…....(11) Cl. dianae var. brevius

36. Cells more curved, curvature more than 110º

39. Poles narrowly and obliquely truncate

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40. Larger, cell wall punctuate, dorsal wall angularly curved

………..…(9) Cl. calosporum var. maius

40. Shorter, cell wall smooth, dorsal wall smoothly curved

….. (8) Cl. calosporum var. calosporum f. erectum

39. Poles sharply rounded

41. Larger in size, small portion of the midregion tumid, strongly

curved……………………..….………(39) Cl. parvulum var. maius

41. Relatively small, midregion more or less retuse

42. Apex pointed, broader………….(37) Cl. parvulum var. parvulum

42. Apex blunt, less broader……...…(40) Cl. parvulum var. obtusum

31. Cells smaller, less than 100 µm. in length

43. Apex acutely pointed

44. Cell dimension small, narrow, 10-13 times longer than broad

…...………….(24) Cl. incurvum forma 2

44. Cell dimension relatively higher, stouter, 6-7 times longer than broad

45. Angle of arc greater than 170º...........(22) Cl. incurvum var. incurvum

45. Angle of arc less than 170º………..………(23) Cl. incurvum forma 1

43. Apex narrow but bluntly pointed

46. Cells much smaller, less than 40µm. long

………(63) Cl. venus var. venus f. minor

46. Cells relatively larger, greater than 40µm. long

47. Cells much stouter, arc is higher, more than 175º

………………..(64) Cl. venus f. crassum

47. Cells slightly slender, arc less than 170º

……….(62) Cl. venus var. venus f. venus

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1. Cells with a girdle band

48. Cells straight or bow shaped, angle of arc less than 60º

49. Apex truncate or broadly rounded

50. Cell wall striated

51. Apex slightly enlarged, sometimes with sub-polar thickening

52. Cells slightly inflated in the midregion

…..(55) Cl. striolatum var. subtruncatum

52. Cells not inflated in the midregion

53. Apex truncate, narrower………………(53) Cl. striolatum var. erectum

53. Apex broadly rounded, broader..…(54) Cl. striolatum var. subdirectum

51. Apex not enlarged and without any sub-polar thickening

54. Wall striations interrupted and broken, cell dimension smaller

…………………….(56) Cl. subcosticum

54. Wall striations continuous, cell dimension higher

………………...(58) Cl. subjuncidiforme

50. Cell wall smooth

55. Cells slender, 14-20 times longer than broad

56. Midregion slightly inflated, cells 260-270 µm. long...…..(41) Cl. planum

56. Midregion not inflated, cells 675-680 µm. long

…………….(52) Cl. sikkimicum sp. nov.

55. Cells rather stout, 9-10 times longer than broad

57. Curvature more than 60º…………...………(2) Cl. abruptum var. brevius

57. Curvature less than 60º………….………(1) Cl. abruptum var. abruptum

49. Apex narrow or sometimes bluntly pointed

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58. Cells broader, 5-7 times longer than broad

59. Cells slightly curved, 63º of arc, cell wall striated

…(50) Cl. rostratum var. sikkimicum var. nov.

59. Cells almost straight, 44º of arc, cell wall punctate

…..(42) Cl. pritchardianum var. pritchardianum f. attenuata

58. Cell slender, 12-52 times longer than broad

60. Cell wall striated, apical extension long, seta-like……....(25) Cl. kuetzingii

60. Cell wall smooth, apex not extended into seta-like process

………………………...(19) Cl. elenkinii

48. Cells strongly curved, lunate, angle of arc more than 60º

61. Apex acutely pointed

62. Cell dimension small, 52-55 µm long, ventral margin in the midregion

almost straight……………………………..(44) Cl. pseudoincurvum sp. nov.

62. Cell dimension larger, 193-196 µm long, ventral margins curved

...………(43) Cl. pseudocynthia sp. nov.

61. Apex narrowly rounded

63. Cell wall striated……………………………..………………(10) Cl. cynthia

63. Cell wall smooth………………………………………….(59) Cl. tacomense

1. Closterium abruptum West var. abruptum

(West 1892, p. 719, pl. 9, f. 1; West & GS West 1904, p. 158, pl. 20, f. 6-10;

Krieger 1937, p. 306, pl. 21, f. 9, pl. 22, f. 5-7; Prescott et al. 1975, p. 25, pl. 18,

f. 9, 12; Lenzenweger 1996, p. 31, pl. 5, f. 4)

[Pl. XVIII, f. 341-343]

Cells elongate, 9-11 times longer than broad, almost straight or slightly curved in

midregion but more curved toward the extremities having 53-67° of arc,

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gradually but slightly attenuated toward the broadly truncated poles; wall smooth

and colourless; girdle bands distinctly present, single; chloroplast with 6

longitudinal ridges with an axial row of 2-3 pyrenoids in each chloroplast.

Length: 146-154µm, Breadth: 15-17 µm, Apex: 6-8 µm.

Collection No. DD-409, 06.11.2009, Mamencho Lake, Sikkim. In association

with yellowish-green filaments on the surface of the water (pH 6, temp. 10ºC).

DD-757, Lava, West Bengal. In association with wet mosses growing on the

surface of the soil (pH 6, temp. 16ºC).

Indian distribution: Madhya Pradesh (Agarkar & Agarkar 1977; Agarkar et al.

1979), West Bengal (Pal & Santra 1993); Hatia Dam, Ranchi (Sharan & Sinha

2010).

This is the first report of the taxon from Eastern Himalaya.

2. Closterium abruptum West var. brevius (West et GS West) West et GS West

(West & GS West 1904, p. 160, pl. 20, f. 11,12; Krieger 1937, p. 308, pl. 22, f.

10; Prescott et al. 1975, p. 26, pl. 18, f. 10,17; Lenzenweger 1996, p. 31, pl. 5, f.

5)

[Pl. XIII, f. 286, 287]

Cell shorter and stouter, 9-11 times longer than broad, almost straight in the

midregion but more curved towards the extremities, gradually but slightly

attenuated toward the broadly truncated poles having 60-70° of arc; wall smooth

and slightly brown in colour; girdle bands present, two in number.

Length: 166-169 µm, Breadth: 15-17µm, Apex: 7-8 µm.

Collection No. DD-418, 06.11.2009, Mamencho Lake, Sikkim. In association

with green filaments on the surface of the water (pH 6, temp. 10ºC).

Indian distribution: Andhra Pradesh (Suxena & Venkateswarlu 1966); Gujarat

(Patel 1979); Bandhabgarh, Madhya Pradesh (Agarkar et al. 1979); Bareilly,

Uttar Pradesh (Pandey et al. 1987); Ranchi (Das 2007); Mamencho Lake, Sikkim

(Das & Keshri 2012).

3. Closterium acerosum (Schrank) Ehrenberg var. tumidum Borge

(Krieger 1937, p. 319, pl. 24, f. 7; Prescott et al. 1975, p. 29, pl. 13, f. 12)

[Pl. IX, f. 269]

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Cells large, 8-9 times longer than broad, slightly curved, almost straight,

narrowly fusiform, stout, 49-58° of arc; the inner margin slightly convex in the

midregion, dorsal margin convex, gradually attenuated to the poles forming

truncately rounded apices; chloroplast axial having several pyrenoids; cell wall

smooth.

Length: 215-354 µm, Breadth: 29-44 µm, Apex: 6-10 µm.

Collection No. DD-418, 06.11.2009, Mamencho Lake, Sikkim. In association

with green filaments on the surface of the water (pH 6, temp. 10ºC).

Indian distribution: Kashmir (Suxena & Venkateswarlu 1968b); Uttarakhand

(Misra et al. 2007).

This is the first report of the taxon from Eastern Himalaya.

4. Closterium acutum Brébisson

(West & GS West 1904, p. 177, pl. 23, f. 9-14; Krieger 1937, p. 259, pl. 13, f. 10-

13; Prescott et al. 1975, p. 30, pl. 16, f. 23, 24; Lenzenweger 1996, p. 32, pl. 2, f.

7-9)

[Pl. XVII, f. 330, 331]

Cells small, needle shaped, 14-21 times longer than broad, straight, 14° of arc

very much less than the typical; lateral margins very slightly curved, gradually

attenuated to the acutely rounded poles; cell wall smooth and colourless;

chloroplast axial with 4 axial pyrenoids.

Length: 81-84 µm, Breadth: 4-6 µm, Apex: 1-2 µm.

Arc is less in the present taxon.

Collection No. DD-380, 06.11.2009 Bitang-cho Lake, Sikkim. In association

with green scum in a swamp (pH 6, temp. 10ºC); DD-724, 02.05.2010,

Kalimpong. In association with brown scum with wet mosses beside a drain (pH

6.5, temp. 24ºC).

Indian distribution: Gujarat (Kamat 1962); Andhra Pradesh (Suxena &

Venkateswarlu 1966a); Nainital (Kamat 1973); Maharashtra (Kamat 1968a,

1973, 1974, 1975); Shillong, Meghalaya (Gupta 2002).

This is the first report of the taxon from Sikkim.

5. Closterium arcuarium Hughes var. arcuarium

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(Hughes 1952, p. 272, f. 23, 27, 57; Prescott et al. 1975, p. 34, pl. 19, f. 4)

[Pl. XXI, f. 367-369]

Cells elongate, 9-12 times longer than broad, moderately curved having 56-89º of

arc, ventral midregion evenly inflated; outer margin convex and inner margin

slightly convex at the midregion instead being concave; cells gradually

attenuated toward the apices; apex broadly attenuated; chloroplast with 7-9

pyrenoids in a series; cell wall smooth, colourless.

Length: 295-305 µm, Breadth: 25-44 µm, Apex: 3-4 µm.

Our specimens are larger than the type.

Collection No. DD-422, 06.11.2009, Mamencho Lake, Sikkim. In association

with light green filaments floats freely on the surface of the water (pH 6, temp.

10ºC).

Indian distribution: Mamencho Lake, Sikkim (Das & Keshri 2012).

6. Closterium arcuarium Hughes var. sikkimense var. nov.

[Pl. XVIII, f. 336]

Cells moderaltely large, 8-9 times longer than broad, curvature is less, 56° of arc;

midregion tumid for about half of its length, dorsal margin evenly convex,

gradually narrowed to the poles, apex bluntly flat with rounded angles; cell wall

smooth and colourless; chloroplast with 3-5 pyrenoids.

Length: 245-250 µm, Breadth: 28-30 µm, Apex: 5-6 µm.

Present specimen differs from the typical one in several respects. i.e.

1. Greater dimension

2. Less angle of arc

3. Apex flat

4. Cell wall colourless

5. Slightly stouter.

Holotype No. DD-414, 06.11.2009, Mamencho Lake, Sikkim. In association

with green filamentous mass attached to the surface of the submerged aquatic

plants (pH 6, temp 10ºC). Kept in the algae herbarium, Department of Botany,

The University of Burdwan (BURD).

7. Closterium bitangchoianum sp. nov.

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[Pl. XVIII, f. 337, 338]

Cells long, 19-21 times longer than broad, elongate, straight, curvature very little,

17° of arc; lateral walls nearly parallel, very gradually attenuated to apices, apex

rounded and very slightly incurved; cell wall smooth and colourless, chloroplast

with 5 pyrenoids in series.

Length: 103-110 µm, Breadth: 5-6 µm, Apex: 2-3 µm.

Present specimen morphologically looks like Cl. aciculare West & Cl.

polystictum Nygaard but differs from both in many respects, viz.

From Cl. aciculare West by:

1. L/B ratio much less

2. Not incurved or pointed at ends

3. Terminal vacuoles not present

4. Length much small.

From Cl. polystictum Nygaard by:

1. Being not pointed

2. Lesser in dimension

3. L/B ratio smaller

4. Much smaller incurved.

Holotype No. DD-379, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with Deep green filamentous mass floating freely on the surface of water forming

bloom (pH 6, temp 10ºC). Kept in the algae herbarium, Department of Botany,

The University of Burdwan (BURD).

8. Closterium calosporum Wittrock var. calosporum f. erectum Prescott

(Prescott et al. 1975, p. 39, pl. 36, f. 11, 14)

[Pl. XIV, f. 298]

Cells medium sized, 9-10 times longer than broad, moderately curved, 118° of

arc; ventral margin straight for 2/3 distance of the margin then curved to the

poles, dorsal margin moderately curved; apex sub-acutely rounded; cell wall

smooth and colourless; chloroplast with 2 axial pyrenoids.

Length: 121-126 µm, Breadth: 13-14 µm, Apex: 4-5 µm.

Collection No. DD-577, 10.11.2009, Sungure, Sikkim. In association with green

filaments on wet rocks in the running water (pH 6, temp 16ºC).

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Indian distribution: This is probably the first report of the taxon from India.

9. Closterium calosporum Wittrock var. maius West et GS West

(Krieger 1937, p. 293, pl. 19, f. 4-7; Prescott et al. 1975, p. 39, pl. 36, f. 7, 9)

[Pl. XX, f. 363, 364]

Cells moderate sized, 9-10 times longer than broad, moderately curved, 121° of

arc; ventral margin straight in the midregion, dorsal margin more curve,

gradually tapering to acutely rounded poles; chloroplast axial with 4 pyrenoids in

each chloroplast; cell wall finely punctate.

Length: 171-173 µm, Breadth: 17-19 µm, Apex: 2-3 µm.

Collection No. DD-419, 06.11.2009, Mamencho Lake, Sikkim. In association

with brownish scum on the surface of the wet rocks (pH 6, temp 10ºC).

Indian distribution: Andaman (Prasad & Misra 1984, 1992; Prasad et al. 1984);

Jalgaon, North Maharashtra (Mahajan & Nandan 2008).

This is the first report of the taxon from Eastern Himalaya.

10. Closterium cynthia De Notaris var. cynthia

(West & GS West 1904, p. 113, pl. 11, f. 1-3; Krieger 1937, p. 365, pl. 35, f. 6-

10; Prescott et al. 1975, p. 45, pl. 35, f. 3, 4, 12)

[Pl. XIX, f. 353-356]

Cells moderately small, 8-13 times longer than broad, moderately curved, 125° of

arc; ventral margin usually strongly concave, the outer wall convex gradually

attenuated at the apices forming obtusely rounded poles; chloroplast axial with 4-

7 pyrenoids in each chloroplast; cell wall with strong striations; girdle band

present.

Length: 49-111 µm, Breadth: 4-10 µm, Apex: 2-5 µm.

The present specimen tallies with the typical but with having less arc.

Collection No. DD-483 09.11.2009, Khechiperi Lake, Sikkim. From the water

squished from the bog pool (pH 6, temp. 14°C). DD- 382, 06.11.2009, Bitang-

cho Lake, Sikkim. In association with Green filamentous mass attached to the

surface of the submerged aquatic plants (pH 6, temp 10ºC).

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Indian distribution: East India (Turner 1892); Vidarbh, Maharashtra (Kamat

1975); Karnataka and Goa (Bharti & Hegde 1982a); Kerala (Shaji et al. 1988);

Banjara and Nadimi Lakes, Andhra Pradesh (Johnson 2006); Kalimpong (Santra

& Pal 2006); Kitham Lake, Agra (Tiwari & Chauhan 2006); Jalgaon, North

Maharashtra (Mahajan & Nandan 2008); Uttar Pradesh (Shukla et al. 2008).

11. Closterium dianae Ehrenberg var. brevius (Petkoff) Krieger

(Krieger 1937, p. 296, pl. 19, f. 3; Prescott et al. 1975, p. 47, pl. 23, f. 9, 13)

[Pl. XIV, f. 297]

Cells small; 12-14 times longer than broad, moderately curved, 106° of arc;

ventral margin concave, dorsal margin more curved, narrowed at the poles

forming attenuated apices; chloroplast axial with 2-3 pyrenoids; cell wall smooth

and colourless.

Length: 122-126 µm, Breadth: 9-10 µm, Apex: 1-3 µm.

Collection No. DD-412, 06.11.2009, Mamencho Lake, Sikkim. In association

with dark greenish filament floating freely on the surface of water (pH 6, temp

10ºC).

Indian distribution: Gujarat (Patel 1979); Bareilly, Uttar Pradesh (Pandey et al.

1987); Nagpur, Maharashtra (Tarar et al. 1998).

This is the first report of the taxon from Eastern Himalaya.

12. Closterium dianae Ehrenberg var. minor Hieronymus

(Krieger 1937, p. 19, pl. 19, f. 15 as Cl. dianae Ehrenberg var. minus (Wille)

Schröder; Prescott et al. 1975, p. 47, pl. 23, f. 8, 12)

[Pl. XVII, f. 324, 325]

Cells small, 6-8 times longer than broad; moderately curved, 111° of arc, dorsal

margin more curved than the ventral, gradually narrowed at the apices forming

attenuated-rounded poles; chloroplast axial with 2 pyrenoids in each semicells;

cell wall smooth and colourless; inner thickening of the wall at the apex is

present.

Length: 95-101 µm, Breadth: 12-15 µm, Apex: 2-3 µm.

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Collection No. DD-419, 06.11.2009, Mamencho Lake, Sikkim. In association

with brownish-yellow filamentous algal mass floating freely on the surface of the

water (pH 6, temp 10ºC).

Indian distribution: Kodaikanal, (Bharati & Pai 1972); Bareilly, Uttar Pradesh

(Pandey & Habib 1987); Basti, Uttar Pradesh (Misra et al. 2001).

This is the first report of the taxon from Eastern Himalaya.

13. Closterium eboracense (Ehrenberg) Turner

(West & GS West 1904, p. 140, pl. 16, f. 7, 8; Krieger 1937, pl. 17, f. 4; Prescott

et al. 1975, p. 48, pl. 21, f. 2)

[Pl. XVII, f. 321, 322]

Cells large, 5-7 times longer than broad, moderately curved, 102-109° of arc;

ventral margin only slightly tumid in the midregion, outer margin strongly

convex, gradually attenuated to broadly rounded poles; chloroplast with 8

longitudinal ridges having several pyrenoids in series or sometimes scarreredly

disposed; cell wall smooth, colour slightly reddish-brown; terminal vacuoles with

granules.

Length: 265-280 µm, Breadth: 38-53 µm, Apex: 5-7 µm.

Collection No. DD-358, 13.05.2009, Bulbulay, Sikkim. With phytoplankton

sample collected from a shallow rock pool (pH 6, temp 17ºC). DD-728,

02.05.2010, Mach pokhri, West Bengal. With phytoplankton sample collected

from the water body (pH 6.5, temp. 22ºC).

Indian distribution: East India (Turner 1892); Gangtok, Sikkim (Prasad & Misra

1987).

14. Closterium eboracense (Ehrenberg) Turner forma

[Pl. XXIII, f. 393]

Cells small, 5-6 times longer than broad, stout, moderately curved, 117° of arc;

ventral margin very slightly tumid in the midregion, gradually narrowed to the

apex; poles broadly rounded; cell wall smooth, colour-less; chloroplast with 6

longitudinal ridges having 2 pyrenoids in each.

Length: 77-80 µm, Breadth: 13-15 µm, Apex: 4-5 µm.

Present specimen differ from the typical by,

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1. Smaller dimension

2. Cell wall colourless.

Collection No. DD-506, 10.11.2009, Changey falls, Sikkim. In association with

dark brown scum on the surface of the rocks under flowing water (pH 6, temp

14ºC).

15. Closterium ehrenbergii Meneghini ex Ralfs var. ehrenbergii

(West & GS West 1904, p. 143, pl. 17, f. 1-4; Krieger 1937, p. 285, pl. 17, f. 1,

pl. 18, f. 1; Prescott et al. 1975, p. 83, pl. 31, f. 3, 12; Lenzenweger 1996, p. 39,

pl. 3, f. 10)

[Pl. XVII, f. 323]

Cells large, 4-6 times longer than broad, stout, moderately curved, 115° of arc;

ventral margin concave but prominently tumid in the midregion, dorsal wall

strongly convex, gradually attenuated to rounded apex; cell wall smooth, light

brown in colour; chloroplast filling the entire space of the cell and having 8

longitudinal ridges with numerous scatterdly arranged pyrenoids; terminal

vacuoles with numerous granules aggregated.

Length: 232-239 µm, Breadth: 45-48 µm, Apex: 6-7 µm.

Collection No. DD-350, 13.05.2009, Bulbulay, Sikkim. In association with

phytoplankton as powdery scum with mosses in a shady place (pH 6, temp 17ºC).

DD-714, 01.05.2010, Kalimpong. With phytoplankton sample collected from a

roadside water body (pH 6.5, temp. 25ºC).

Indian distribution: Banaras, Uttar Pradesh (Venkataraman 1957); Varuna,

Varanasi (Prasad 1964-65); Amritsar, Punjab (Singh 1966); Andhra Pradesh

(Suxena & Venkateswarlu 1968b); Gwalior, Madhya Pradesh (Agarkar 1969;

Agarkar & Agarker 1972); Vidarbh, Maharashtra (Kamat 1975); Nagpur (Freitas

& Kamat 1979); Gujarat (Patel 1979); Karnataka and Goa (Bharti & Hegde

1982); Kashmir (Compère 1983); Bareilly, Uttar Pradesh (Pandey & Habib

1987); Bareilly, Uttar Pradesh (Pandey et al. 1987); Jalgaon, North Maharashtra

(Mahajan & Nandan 2008); Shillong (Das et al. 2009); Eastern Himalaya

(Yasmin et al. 2011).

16. Closterium ehrenbergii Meneghini ex Ralfs var. ehrenbergii forma

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[Pl. XVI, f. 312, 313]

Cells large, 4-5 times longer than broad, stout, moderately curved, 121° of arc;

both the ventral and dorsal margins elevated distinctly in the midregion, dorsal

margin strongly curved but ventral wall less curved, gradually attenuated to the

apex; poles broadly rounded; cell wall smooth and colourless; chloroplast with

several pyrenoids in series.

Length: 215-225 µm, Breadth: 48-55 µm, Apex: 5-5 µm.

Present specimen differs from the typical by having distinctly elevated

midregion.

Collection No. DD-358, 13.05.2009, Bulbulay, Sikkim. With phytoplankton

sample collected from a shallow rock pool (pH 6, temp 17ºC).

17. Closterium ehrenbergii Meneghini ex Ralfs var. malinvernianum (De Notaris)

Rabenhorst

(West & GS West 1904, p. 145, pl. 17, f. 5, 6 as Cl. malinvernianum De Notaris;

Krieger 1937, p. 287, pl. 18, f. 2; Prescott et al. 1975, p. 50, pl. 21, f. 7;

Lenzenweger 1996, p. 39)

[Pl. XIII, f. 284, 285, 288, 289]

Cells large, 5-7 times longer than broad; moderately curved, 98-114° of arc;

ventral margin concave but inflated in the midregion, dorsal wall strongly

convex, gradually attenuated to rounded poles; chloroplast axial with numerous

scattered pyrenoids; cell wall striated and colourless.

Length: 247-305 µm, Breadth: 44-46 µm, Apex: 6-7 µm.

Collection No. DD-488, 09.11.2009, Khechiperi Lake, Sikkim. In association

with blackish mass with weeds (Potamogeton sp.) lodged on roots. DD-391,

06.11.2009, Bitang-cho Lake. Sikkim. In association with brownish scum

attached to the surface of the submerged part of the semi-aquatic plants (pH 6,

temp 10ºC).

Indian distribution: Uttar Pradesh (Sarma 1962; Prasad & Mehrotra 1977);

Andhra Pradesh (Suxena & Venkateswarlu 1968a); Gujarat (Patel 1979);

Bareilly, Uttar Pradesh (Pandey et al. 1988).

This is the first report of the taxon from Eastern Himalaya.

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18. Closterium ehrenbergii Meneghini ex Ralfs var. podolicum Gutwinski

(Krieger 1937, p. 288, pl. 18, f. 5; Prescott et al. 1975, p. 50, pl. 20, f. 2, 7)

[Pl. XX, f. 359, 360]

Cells large, 4-5 times longer than broad; moderately curved, 115° of arc; ventral

margin straight at the midregion, the dorsal margin strongly curved, tapering

gradually and then abruptly in the apical region with apex slightly re-curved; cell

wall smooth and colourless.

Length: 470-480 µm, Breadth: 93-97 µm, Apex: 5-7 µm.

Collection No. DD-31, 16.04.2009. Pelling, Sikkim. In association with wet

mosses on the bark of a tree (pH 6, temp 21ºC).

Indian distribution: This is probably the first report of the taxon from India.

19. Closterium elenkinii Kossinskaja

(Prescott et al. 1975, p. 51, pl. 19, f. 1-3)

[Pl. XIX, f. 351, 352]

Cells medium sized, 12-14 times longer than broad, slightly swollen in the

midregion, 71°of arc, narrowing abruptly toward the apical region with the apices

slightly produced; chloroplast with 4 longitudinal ridges with 4 pyrenoids in each

chloroplast; cell wall smooth; apical regions with vibrating granules.

Length: 255-264 µm, Breadth: 18-21 µm, Apex: 3-6 µm.

Collection No. DD- 412, 06.11.2009, Mamencho Lake, Sikkim. In association

with green filaments attached on the surface of the partially submerged rocks (pH

6, temp. 10ºC).

Indian distribution: This is probably the first report of the taxon from India.

20. Closterium gracile Brébisson ex Ralfs var. gracile

(West & GS West 1904, p. 166, pl. 21, f. 8-10; Krieger 1937, pl. 30, f. 7-9;

Prescott et al. 1975, p. 52, pl. 16, f. 2, 15, 16; Lenzenweger 1996, p. 39, pl. 5, f.

1)

[Pl. XIX, f. 357, 358]

Cells medium sized, 25-36 times longer than broad, slender, almost straight for

more than two-third the length, curvature 37° of arc; margins parallel, gradually

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narrowed and gracefully curved toward the apical region, poles obtuse; cell wall

smooth and colourless; chloroplast with 14 pyrenoids.

Length: 144-151 µm, Breadth: 4-6 µm, Apex: 2-3 µm.

Collection No. DD-413, DD-414, DD-415, 06.11.2009, Mamencho Lake,

Sikkim. In association with green filaments attached on the surface of the

partially submerged rocks (pH 6, temp 10ºC). DD-125, 18.04.2009, Khechiperi

Lake, Sikkim. In association with brownish wooly masses growing in water (pH

5 temp. 19ºC).

Indian distribution: Karnataka (Bharati 1965); Andhra Pradesh (Suxena &

Venkateswarlu 1968a); Maharashtra (Kamat 1968); Gwalior, Madhya Pradesh

(Agarkar 1969); Vidarbh, Maharashtra (Kamat 1975); Gujarat (Patel 1979);

Karnataka and Goa (Bharti & Hegde 1982); Rohilakhand, Uttar Pradesh

(Chaturvedi 1975); Bareilly, Uttar Pradesh (Pandey et al. 1987); Hamirpur, Uttar

Pradesh (Habib & Chaturvedi 2007); Sitapur, Uttar Pradesh (Habib 2008);

Hardoi, Uttar Pradesh (Habib 2009); Kumayun Himalaya (Habib &Chaturvedi

2011); Karnataka (Venkateshwarlu et al. 2011); Dehradun, Uttarakhand (Habib

& Chaturvedi 2012).

This is the first report of the taxon from Eastern Himalaya.

21. Closterium gracile Brébisson ex Ralfs var. tenue (Lemmermann) West et West

(West & GS West 1904, p. 168, pl. 21, f. 13; Prescott et al. 1975, p. 53, pl. 16, f.

7)

[Pl. XXIII, f. 388-392]

Cells medium sized, slender, narrow, 13-23 times longer than broad, slightly

curved (30-35º), almost straight for more than one-half of the length; margins

parallel, gradually narrowed and curved toward the apical region, poles obtuse;

chloroplast axial with 7 pyrenoids; cell wall smooth and colourless.

Length: 67-141 µm, Breadth: 3-7 µm, Apex: 1-3 µm.

Collection No. DD-380, 06.11.2009 Bitang-cho Lake, Sikkim. In association

with green scum in a swamp (pH 6, temp. 10ºC). DD-27, 16.04.2009, Pelling.

With phytoplankton samples collected from a small Lake (pH 5, temp 21ºC).

DD-489, Khechiperi Lake, Sikkim. In association with green filaments growing

attached on pebbles & submerged weeds (pH 6, temp 14ºC).

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Indian distribution: This is probably the first report of the taxon from India.

22. Closterium incurvum Brébisson var. incurvum

(West & GS West 1904, p. 136, pl. 15, f. 28-30; Prescott et al. 1975, p. 53, pl. 36,

f. 5, 6; Lenzenweger 1996, p. 40, pl. 2, f. 22-24)

[pl. XVIII, f. 339, 340]

Cells small, 6-7 times longer than broad, strongly curved, 173°of arc, ventral

margin not inflated, strongly attenuated to the apical region, the poles acutely

rounded; chloroplast axial plate with single pyrenoid in each; cell wall smooth

and colourless.

Length: 61-66 µm, Breadth: 9-11 µm, Apex: 1-4 µm.

The present specimen appears an intermediate form between Cl. incurvum

Brébisson & Cl. venus Kützing ex Ralfs since the arc is 172º. Krieger (1937)

considered Cl. incurvum Brébisson synonymous with Cl. venus Kützing ex Ralfs

but Prescott (1975) considered it as a separate species. Since the present form

appears closer in morphology to Cl. incurvum Brébisson it has been considered

here but it differs slightly from the type in certain respect,

1. Little less angle of arc

2. Presence of single pyrenoid in each semicell.

Collection No. DD-416, 06.11.2009, Mamencho Lake, Sikkim. In association

with Brownish scum attached to the surface of the submerged parts of the semi-

aquatic plants (pH 6, temp 10ºC).

Indian distribution: Eastern India (Turner 1892); Karnataka (Bharati 1965);

Vidarbh, Maharashtra (Kamat 1975); Kashmir (Compère 1983); Basti, Uttar

Pradesh (Misra et al. 2001); Bihar (Kumar & Chaudhary 2009); Eastern

Himalaya (Yasmin et al. 2011).

23. Closterium incurvum Brébisson forma 1

[Pl. XIX, f. 350]

Cells small, 5-7 times longer than broad, strongly curved, but less than the

typical, 168°of arc, both the dorsal and ventral margins similarly curved,

attenuated to the apex; apex acutely pointed; cell wall smooth and colourless;

chloroplast axial plate with several pyrenoids.

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Length: 46-51 µm, Breadth: 8-9 µm, Apex: 3-5 µm.

Present taxon very much similar to the typical but differs in,

1. Cell less curved

2. Apex acutely pointed.

Collection No. DD-380, 06.11.2009 Bitang-cho Lake, Sikkim. In association

with green scum in a swamp (pH 6, temp. 10ºC).

24. Closterium incurvum Brébisson forma 2

[Pl. XXIII, f. 394, 395]

Cells small, narrow, 10-13 times longer than broad, strongly curved, but much

less than the type, 147°of arc; both the dorsal and ventral margins equally curved,

attenuated to the apex; poles strongly pointed; cell wall smooth and colourless.

Length: 39-42 µm, Breadth: 3-4 µm, Apex: 1-2 µm.

Present taxon very much similar to the typical but differs in,

1. Cell less curved

2. Cells less broad, narrower.

Collection No. DD-414, 06.11.2009, Mamencho Lake, Sikkim. In association

with green filamentous mass attached to the surface of the submerged aquatic

plants (pH 6, temp 10ºC).

25. Closterium kuetzingii Brébisson var. kuetzingii

(West & GS West 1904, p. 186, p. 25, f. 6-11; Krieger 1937, p. 351, pl. 32, f. 8,

9; Prescott et al. 1975, p. 57, pl. 31, f. 6, 7, 15; Lenzenweger 1996, p. 42, pl. 6, f.

7)

[Pl. IX, f. 270, 271]

Cells long, 48-52 times longer than broad, almost a straight, curvature 40° arc;

only apex slightly incurved, the midregion fusiform-lanceolate, the dorsal and

ventral margins about equally convex, attenuated abruptly toward the apical

margins to form setaceous processes, the poles rounded and often slightly

inflated, with an inner wall thickening; cell wall brownish yellow, striated, 10

striae in 10 µm.

Length: 471-508 µm, Breadth: 9-19 µm, Apex: 3-7 µm.

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Collection No. DD-382, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with green filamentous mass attached to the surface of the submerged aquatic

plants (pH 6, temp 10ºC). DD-584, 12.11.2009, Namchi, Sikkim. In association

with greenish scum with wet mosses growing on soil (pH 6.5, temp. 15ºC). DD-

717, 01.05.2010, Kalimpong. With phytoplankton sample collected from a small

waterbody (pH 6.5, temp. 25ºC).

Indian distribution: Eastern India (Turner 1892); Kodaikanal, Tamilnadu

(Iyengar & Vimla Bai 1941; Singh & Balasingh 2011); Maharashtra (Bharati

1965a; Kamat 1968a); Andhra Pradesh (Suxena & Venkateswarlu 1968a); Simla,

Himachal Pradesh (Kamat 1968b); Madhya Pradesh (Agarkar 1971; Agarkar &

Agarker 1973); Vidarbh, Maharashtra (Kamat 1975); Gujarat (Patel 1979);

Allahabad (Pandey & Pandey 1980a); Karnataka and Goa (Bharti & Hegde

1982); Savandurga, Karnataka (Gurudeva et al. 1983); Bareilly, Uttar Pradesh

(Pandey et al. 1987); Muriyad, Kerala (Sanilkumar & Thomas 2006); Hamirpur,

Uttar Pradesh (Habib & Chaturvedi 2007); Uttarakhand (Misra et al. 2008); Bihar

(Kumar & Chaudhary 2009); Goalpara, Assam (Deca et al. 2011); Eastern

Himalaya (Yasmin et al. 2011).

26. Closterium libellula Focke ex Nordstedt var. libellula f. libellula

(Krieger 1937, p. 254, pl. 12, f. 1, 2; Prescott et al. 1975, p. 607, pl. 12, f. 12)

[Pl. XVI, f. 319, 320]

Cells small, 4-4.5 times longer than broad, straight, 18˚ of arc, attenuated from

the midregion to broadly truncate poles; poles broadly rounded; cell wall smooth;

chloroplast with 10 longitudinal ridges with 2-4 pyrenoids in each; terminal

vacuoles with several small granules.

Length: 117-140 µm, Breadth: 26-28 µm, Apex: 6-7 µm.

Collection No. DD-129, 18.04.2009, Khechiperi Lake, Sikkim. In association

with green filaments growing attached on pebbles & submerged weeds (pH 6.5,

Temp. 14°C).

Indian distribution: East India (Turner 1892); Kodaikanal, South India (Iyenger

& Vimla Bai 1941; Bharati & Pai 1972); West Bengal (Roy 1955); Pakhal Lake,

Andhra Pradesh (Suxena & Venkateswarlu 1966a); Mount Abu, Rajasthan

(Kamat 1967); Vidyan Region, Madhya Pradesh (Agarkar & Agarkar, 1972);

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Vidarbh, Maharashtra (Kamat 1975); Pachmari, Madhya Pradesh (Agarkar &

Agarkar 1977); Marathwada, Maharashtra (Asthekar & Kamat 1979); Kerala

(Sindhu & Panikkar 1995a).

This is also a fairly common species but sometimes confused with Netrium. This

is the first report of the taxon from Eastern Himalaya.

27. Closterium libellula Focke ex Nordstedt var. intermedium (Roy et Bissett) GS

West

(Krieger 1937, p. 255, pl. 12, f. 3-5; Prescott et al. 1975, p. 61, pl. 12, f. 1, 2)

[Pl. XVII, f. 326, 327]

Cells small, 4-5 times longer than broad, straight, curvature 27° of arc; both

margins concave at the midregion and gradually truncate poles; chloroplast axial;

cell wall smooth and colourless.

Length: 126-129 µm, Breadth: 25-28 µm, Apex: 6-7 µm.

Collection No. DD-578, Sungure, Sikkim. In association with wet mosses as

brown powdery masses from rock wall (pH 6, temp 17ºC).

Indian distribution: Andhra Pradesh (Suxena & Venkateswarlu 1968b);

Gwalior, Madhya Pradesh (Agarkar 1971); Gujarat (Patel 1979); Allahabad

(Pandey & Pandey 1980); Karnataka and Goa (Bharti & Hegde 1982a); Bareilly,

Uttar Pradesh (Pandey et al. 1987); Gangtok, Sikkim (Prasad & Misra 1987);

Kalimpong (Santra & Pal 2006).

28. Closterium libellula Focke ex Nordstedt var. sikkimense var. nov.

[Pl. XVI, f. 314, 315]

Cells straight, 9-10 times longer than broad, straight, 34° of arc; midregion

slightly elevated angularly, gradually attenuated to broadly rounded poles; cell

wall smooth and colourless; chloroplast 2 parted, having 6 longitudinal ridges

with 6-8 pyrenoids,.

Length: 170-180 µm, Breadth: 18-20 µm, Apex: 5-6 µm.

Our species differ from typical and all other existing varieties by,

1. Angular median region

2. Smaller in dimension.

These forms appear intergrading among Penium, Netrium & Closterium.

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Holotype No. DD-382, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with green filamentous mass attached to the surface of the submerged aquatic

plants (pH 6, temp 10ºC). Kept in the algae herbarium, Department of Botany,

The University of Burdwan (BURD).

29. Closterium littorale Gay var. indicum var. nov.

[Pl. XVI, f. 318]

Cells medium sized, 4-6 times longer than broad, stouter than the typical, slightly

curved, 53° of arc; ventral margin slightly swollen in the midregion forming

somewhat angularly elevated portion, dorsal margin convex, uniformly

attenuated to the apex; poles rounded with slight invagination; cell wall smooth

and colourless; chloroplast not ridged.

Length: 129-135 µm, Breadth: 21-28 µm, Apex: 4-6 µm.

Present species resembles much to the Cl. littorale Gay var. littorale but differs:

1. Stouter

2. Apex invaginated

3. Chloroplast not ridged

4. Midregion angularly elevated.

The present variety also resembles C. arcuarium Hughes but differs in

1. Less curved

2. Less longer

3. Apex broader

4. Apex invaginated

5. Chloroplast not ridged.

Holotype No. DD-416, 06.11.2009, Mamencho Lake, Sikkim. In association

with brownish scum attached to the surface of the submerged part of the semi-

aquatic plants (pH 6, temp 10ºC). Kept in the algae herbarium, Department of

Botany, The University of Burdwan (BURD).

30. Closterium lunula (Müller) Nitzsch ex Ralfs var. lunula f. lunula

(West & GS West 1904, p. 150, pl. 18, f. 8, 9; Krieger 1937, p. 301, pl. 21, f. 1,

pl. 22, f. 1; Prescott et al. 1975, p. 65, pl. 14, f. 3-5)

[Pl. XIX, f. 348]

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Cells moderately large, 4-6 times longer than broad, almost straight, 45° of arc;

dorsal wall more curved than the ventral; ventral wall slightly concave in the

median section, gradually narrowed to the apical region forming broadly rounded

poles; chloroplast axial plate; cell wall smooth & colourless.

Length: 200-259 µm, Breadth: 34-55 µm, Apex: 3-5 µm.

Collection No. DD-79, 17.04.2009, Pelling, Sikkim. In association with bluish

green slimy mass growing in a drain (pH 5.5, temp 26ºC).

Indian distribution: Eastern India (Turner 1892); Savandurga, Karnataka

(Gurudeva et al. 1983); Andhra Pradesh (Sarojini 1996); Maharashtra (Nandan &

Jain 2004); Gomti river (Kumar & Suseela 2004); Uttaranchal (Misra et al.

2009); Karnataka (Venkateshwarlu et al. 2011); Goalpara, Assam (Deca et al.

2011).

31. Closterium lunula (Müller) Nitzsch ex Ralfs var. lunula f. minor West et GS

West

(West & GS West 1904, p. 151; Prescott et al. 1975, p. 66, pl. 14, f. 1, 2)

[Pl. X, f. 272, 273]

Cells large, 5-6 times longer than broad, stout, slightly curved, 54° of arc; ventral

margin very slightly convex, dorsal wall much more curved than the ventral,

gradually narrowed to the poles, apex truncately rounded; cell wall smooth,

slightly yellow in colour; chloroplast with numerous scattered pyrenoids.

Length: 307-316 µm, Breadth: 55-58 µm, Apex: 6-11 µm.

Collection No. DD-380, 06.11.2009 Bitang-cho Lake, Sikkim. In association

with green scum in a swamp (pH 6, temp. 10ºC).

Indian distribution: This is probably the first report of the taxon from India.

32. Closterium mamenchoenum sp. nov.

[Pl. X, f. 274; pl. XI, f. 275]

Cells elongate, 9-10 times longer than broad, almost straight, 53° of arc; median

region straight, not swollen, gradually and uniformly attenuated to the poles;

apex broadly rounded with somewhat swollen; cell wall brownish in colour,

striated, striae thick and prominent, 9-11 striae visible from one side; chloroplast

with 3-6 pyrenoids in a series.

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Length: 345-348 µm, Breadth: 35-36 µm, Apex: 12-15 µm.

Present specimen is much similar to Cl. balmacarense Turner but differs from it

in several respects,

1. Cell wall striated

2. Angle of curvature greater

3. Apex rounded

4. Stouter, breadth of the cell greater.

Holotype No. DD-413, 06.11.2009, Mamencho Lake, Sikkim. In association

with light greenish-yellow filaments attached on the surface of the wet rock (pH

6, temp. 10ºC). Kept in the algae herbarium, Department of Botany, The

University of Burdwan (BURD).

33. Closterium minutum Roll var. indicum var. nov.

[Pl. XIV, f. 294-296]

Cells small, moderately curved, but greater than the typical, 137° of arc, lunate;

both margins equally curved, slightly tapered to bluntly rounded poles;

chloroplast axial plate with 3-4 pyrenoids in series; cell wall smooth and

colourless.

Length: 52-78 µm, Breadth: 8-11 µm, Apex: 3-4 µm.

This specimen is very much similar to the Cl. minutum Roll var. minutum, but

differs from the typical and all other existing varieties by,

1. Greater angle of divergence

2. Longer dimension.

Holotype No. DD-415, DD-417, 06.11.2009, Mamencho Lake, Sikkim. In

association with greenish-brown scum attached to the surface of the wet rock (pH

6, temp. 10ºC). Kept in the algae herbarium, Department of Botany, The

University of Burdwan (BURD).

34. Closterium moniliferum Ehrenberg ex Ralfs var. moniliferum

(West & GS West 1904, p. 142, pl. 16, f. 15, 16; Krieger 1937, pl. 18, f. 6, 7;

Prescott et al. 1975, p. 70, pl. 21, f. 3; Lenzenweger 1996, p. 45, pl. 3, f. 11)

[Pl. XIX, f. 349]

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Cells medium sized, 6-7 times longer than broad, curved, angles of curvature

135° of arc, stout; the outer wall strongly concave and the ventral one somewhat

straight in the midregion, uniformly attenuated to broadly rounded poles;

chloroplast with 6 longitudinal ridges and 3-5 axial pyrenoids in each; cell wall

smooth and colourless.

Length: 264-268 µm, Breadth: 41-44 µm, Apex: 7-8 µm.

Collection No. DD-510, 10.11.2009, Changey falls, Sikkim. In association

withscum on wet rocks beside the falls (pH 6, temp 14ºC).

Indian distribution: Eastern India (Turner 1892); Assam (Brühl & Biswas

1926); Gujarat (Kamat 1962; Patel 1979); Maharashtra (Kamat 1963; Bharati

1965a); Kashmir (Suxena & Venkateswarlu 1968b); Andhra Pradesh (Suxena &

Venkateswarlu 1968c); Rajasthan (Patel & Rao 1975); Uttar Pradesh (Prasad &

Mehrotra 1977b); Allahabad, Uttar Pradesh (Pandey & Pandey 1980);

Savandurga, Karnataka (Gurudeva et al. 1983); Kashmir (Compère 1983);

Madhya (Misra et al. 2008); Jalgaon, North Maharashtra (Mahajan & Nandan

2008); Gangtok, Sikkim (Prasad & Misra 1987).

35. Closterium moniliferum Ehrenberg ex Ralfs var. submoniliferum (Woronichin)

Krieger

(Krieger 1937, p. 292, pl. 18, f. 10; Prescott et al. 1975, p. 71, pl. 21, f. 1)

[Pl. XV, f. 306, 307]

Cells large, 5-7 times longer than broad, moderately curved, 91° of arc, stout; the

outer wall strongly curved, the ventral wall somewhat inflated in the midregion,

uniformly attenuated to broadly rounded poles; chloroplast axial with several

scattered pyrenoids; cell wall smooth and colourless.

Length: 278-299 µm, Breadth: 45-51µm, Apex: 7-9 µm.

Collection No. DD-358, Bulbulay, Sikkim. With phytoplankton samples

collected from a rock pool (pH 6, temp 17ºC). DD-194, 19.04.2009, Yoksum,

Sikkim. In association with greenish filaments in a swamp.

Indian distribution: This is probably the first report of the taxon from India.

36. Closterium navicula (Brébisson) Lutkemuller var. navicula

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(Krieger 1937, p. 257, pl. 12, f. 8-10; Prescott et al. 1975, p. 71, pl. 12, f. 3, 7;

Lenzenweger 1996, p. 45, pl. 3, f. 11)

[Pl. XIV, f. 304]

Cells short, 3-4 times longer than broad, fusiform, not much curved, 78° of arc;

both margins concave, gradually attenuated to broadly rounded apices;

chloroplast having 8 longitudinal ridges with few pyrenoids; terminal vacuole

with granules.

Length: 113-116 µm, Breadth: 35-38 µm, Apex: 6-7 µm.

Present specimen is slightly larger than the type.

Collection No. DD-578, 10.11.2009, Sungure, Sikkim. In association with

phytoplankton lodged in wet mosses growing in a drain (pH 6, temp 16ºC).

Indian distribution: Maharashtra (Bharati 1965a); Andhra Pradesh (Suxena &

Venkateswarlu 1968a); Kashmir (Suxena & Venkateswarlu 1968b); Gwalior,

Madhya Pradesh (Agarkar 1971); Gujarat (Patel 1979); Bareilly, Uttar Pradesh

(Pandey et al. 1987); Kerala (Shaji et al. 1988); Goalpara, Assam (Deca et al.

2011).

37. Closterium parvulum Nageli var. parvulum

(West & GS West 1904, p. 133, pl. 15, f. 9-12; Krieger 1937, p. 275, pl. 16, f. 14-

17; Prescott et al. 1975, p. 73, pl. 24, f. 18-20)

[Pl. XIV, f. 302, 303]

Cells medium sized, 6-7 times longer than broad, moderately curved, 127° of arc;

ventral wall straight at the midregion then gradually curved to the apex, dorsal

margin moderately convex, gradually attenuated to the apex, apex acutely

rounded; cell wall smooth and colourless; chloroplast with 3 axial pyrenoids.

Length: 114-120 µm, Breadth: 17-18 µm, Apex: 3-5 µm.

Collection No. DD-380, 06.11.2009 Bitang-cho Lake, Sikkim. In association

with green scum in a swamp (pH 6, temp. 10ºC). DD-728, 02.05.2010, Mach

pokhri, West Bengal. With phytoplankton sample collected from the waterbody

(pH 6.5, temp. 22ºC).

Indian distribution: Assam (Brühl & Biswas 1926); Maharashtra (Kamat 1963;

Bharati 1965a); Karnataka (Bharati 1965b); Andhra Pradesh (Suxena &

Venkateswarlu 1968c); Gwalior, Madhya Pradesh (Agarkar 1969); Gujarat (Patel

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1979); Vidarbh, Maharashtra (Kamat 1975); Savandurga, Karnataka (Gurudeva

et al. 1983); Kashmir (Compère 1983); Bareilly, Uttar Pradesh (Pandey et al.

1987); Nagpur, Maharashtra (Tarar et al. 1998); Ranchi (Guru 2007);

Kanyakumari (Balasingh & Shamal 2007); Jalgaon, North Maharashtra (Mahajan

& Nandan 2008); Tamil Nadu (Senthilkumar & Sivakumar 2008); Kodaikanal,

Tamilnadu (Singh & Balasingh 2011); Karnataka (Venkateshwarlu et al. 2011);

Goalpara, Assam (Deca et al. 2011).

38. Closterium parvulum Nageli forma

[Pl. XVIII, f. 344, 345]

Cells small, 8-9 times longer than broad, moderately curved, 104° of curvature;

ventral wall slightly concave in the midregion, then curved toward the poles,

apex sharply rounded; cell wall with smooth and colourless; chloroplast with 2-3

pyrenoids.

Length: 120-124 µm, Breadth: 9-11 µm, Apex: 3-5 µm.

Our specimen differs from the typical in following,

1. Less curved

2. Breadth is less.

Collection No. DD-389, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with light green filaments on the surface of the water (pH 6, temp 10ºC).

39. Closterium parvulum Nageli var. maius West

(Krieger 1937, pl. 16, f. 18; Prescott et al. 1975, p. 74, pl. 24, f. 1)

[Pl. XXII, f. 376, 377]

Cells large, 10-12 times longer than broad, strongly curved, 160° of arc, ventral

margin slightly concave in the midregion, gradually attenuated to the apical

region, the poles sharply rounded with slight inner thickening of the wall;

chloroplast axial with 5 pyrenoids in each; cell wall smooth and colourless.

Length: 187-318 µm, Breadth: 14-30 µm, Apex: 2-5 µm.

Collection No. DD-583, 12.11.2009, Namchi, Sikkim. In association with

greenish-brown scum with mosses on a small rock pool (pH 6.5, temp. 14ºC).

DD-757, Lava, West Bengal. In association with wet mosses growing on the

surface of the soil (pH 6, temp. 16ºC).

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Indian distribution: Goalpara, Assam (Deca et al. 2011).

40. Closterium parvulum Nageli var. obtusum Croasdale

(Prescott et al. 1975, p. 74, pl. 24, f. 3)

[Pl. XIV, f. 299, 300]

Cells small, 8-10 times longer than broad, moderately curved, curvature 115° of

arc; ventral wall concave in the midregion, gradually attenuated at the apical

region; the poles bluntly rounded; chloroplast axial with 3-5 pyrenoids; cell wall

smooth and colourless.

Length: 99-102 µm, Breadth: 10-12 µm, Apex: 3-4 µm.

Collection No. DD-379, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with deep green filamentous mass floating freely on the surface of water forming

bloom (pH 6, temp 10ºC).

Indian distribution: This is probably the first report of the taxon from India.

41. Closterium planum Hughes

(Hughes 1952, p. 284, f. 34; Prescott et al. 1975, p. 75-76, pl.17, f. 17)

[Pl. XV, f. 308-311]

Cells elongate, 12-19 times longer than broad, slightly curved having 36-51° of

arc, pole truncated and slightly rounded; cell wall smooth brown in colour; outer

wall slightly more curved than the inner; girdle band present, sometimes not

evident; chloroplast with 6 longitudinal ridges and with 6 axial pyrenoids in each.

Length: 234-270 µm, Breadth: 16-20 µm, Apex: 5-8 µm.

Collection No. DD-415, 06.11.2009, Mamencho Lake, Sikkim. In association

with green filaments on the surface of the water (pH 6, temp 10ºC). DD-833,

12.11.2011, Chage falls, Lava. In association with blackish filament with moss

from decayed bark.

Indian distribution: Pakhal Lake, Andhra Pradesh (Suxena & Venkateswarlu,

1966a), Madhya Pradesh (Agarkar & Agarkar 1977); Mamencho Lake (Das &

Keshri 2012).

42. Closterium pritchardianum Archer var. pritchardianum f. attenuata Irénée-

Marie

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(Prescott et al. 1975, p. 78, pl. 15, f. 12; Lenzenweger 1996, p. 48, pl. 4, f. 15)

[Pl. IX, f. 268]

Cells large, 6-7 times longer than broad; almost straight, 44° of arc; ventral

margin concave, dorsal margin more curved than the ventral, gradually

attenuated to narrowly rounded poles, apex re-curved; girdle band present;

chloroplast axial plate; cell wall with fine striae, regularly distributed all over the

cell wall.

Length: 377-382 µm, Breadth: 55-58 µm, Apex: 4-5 µm.

Collection No. DD-405, 06.11.2009, Changu Lake, Sikkim. In association with

dark green filament on the surface of the water (pH 6, temp 9ºC).

Indian distribution: This is probably the first report of the taxon from India.

43. Closterium pseudocynthia sp. nov.

[Pl. XX, f. 365, 366]

Cells medium sized, 13-15 times longer than broad; moderately curved, 117° of

arc; both the ventral and dorsal margins are equally curved; median portion of the

ventral margin very slightly straight, gradually narrowed to the poles which is

sharply pointed; cell wall smooth and yellowish red in colour; girdle band present

in the midregion of the cell; chloroplast with 4 longitudinal ridges having 5-6

pyrenoids in axial series; terminal vacuoles with 4-5 granules.

Length: 193-196 µm, Breadth: 13-15 µm, Apex: 1-2 µm.

Present taxa resembles very much to the Cl. cynthia De Notoris, but differs in:

1. Absence of vertical striations

2. Poles distinctly pointed

3. Greater L/B ratio

4. Terminal vacuoles with vertical granules.

Holotype No. DD-17, 16.04.2009, Pelling, Sikkim. In association with deep

green slimy filaments on the margin of a water body (pH 5, temp 19ºC). Kept in

the algae herbarium, Department of Botany, The University of Burdwan

(BURD).

44. Closterium pseudoincurvum sp. nov.

[Pl. XXII, f. 382, 383]

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Cell small, 7-9 times longer than broad, strongly curved, 156° of arc; dorsal

margin strongly convex but median portion of ventral margin nearly straight;

midregion slightly inflated, strongly narrowed to the apical region forming

acutely pointed poles; girdle band present in the midregion, cell wall otherwise

smooth and colourless; chloroplast axial plate.

Length: 52-55 µm, Breadth: 6-7 µm, Apex: 1-2 µm.

Present taxon mush resembles Cl. incurvum Brébisson but differs in,

1. Apex abruptly attenuated to slender points

2. Mid region of ventral margin more or less straight

3. Girdle band present.

Also similar to Cl. acutum Brébisson but differs in,

1. Midregion thick with ventral side more or less straight

2. Higher angle of arc

3. Transverse girdle present.

Holotype No. DD-420, 06.11.2009, Mamencho Lake, Sikkim. In association

with light green filaments on the surface of the water (pH 6, temp 10ºC). Kept in

the algae herbarium, Department of Botany, The University of Burdwan

(BURD).

45. Closterium pseudolunula Borge

(Krieger 1937, p. 305, pl. 22, f. 3; Prescott et al. 1975, p. 79, pl. 19, f. 15;

Lenzenweger 1996, p. 48, pl. 4, f. 1)

[Pl. XVIII, f. 332-335]

Cells medium sized, 6-10 times longer than broad; moderately curved, 44-75°

angle of arc; the dorsal margin convex, the ventral margin straight for more than

two third of the length; apex broadly rounded; chloroplast axial with 4-5

pyrenoids in each; cell wall smooth and colourless.

Length: 204-258 µm, Breadth: 23-31 µm, Apex: 4-11 µm.

One of the specimens differs in,

1. Chloroplast not ridged

2. No terminal vacuoles present

3. Apex broader.

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Collection No. DD-415, 06.11.2009, Mamencho Lake, Sikkim. In association

with greenish-brown scum on the surface of the wet rock (pH 6, temp 10ºC). DD-

628, 04.05.2010, Gurudongmar Lake, Sikkim. In association with green filaments

on the wet rock beside the Lake (pH 6, temp 9ºC). DD-717, 01.05.2010,

Kalimpong. With phytoplankton sample collected from a small water body (pH

6.5, temp. 25ºC).

Indian distribution: Gwalior, Madhya Pradesh (Agarkar 1971); Gujarat (Patel

1979); Kashmir (Compère 1983); Bareilly, Uttar Pradesh (Pandey & Habib

1987); Goalpara, Assam (Deca et al. 2011).

46. Closterium rectimarginatum Scott et Prescott

(Scott & Prescott 1961, p. 13, pl. 1, f. 27, 28; Ling & Tyler 1986, p. 18, pl. 5, f.

31)

[Pl. IX, f. 267]

Cells large, 7-8 times longer than broad; spindle shaped, straight, 32° of arc;

lateral margins almost straight, slightly convex, dorsal margin more curved than

the ventral, attenuated at the apex to form tuncately rounded poles; cell wall

smooth and colourless; chloroplast with axial series of several pyrenoids.

Length: 423-426 µm, Breadth: 56-58 µm, Apex: 9-10 µm.

Collection No. DD-379, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with deep green filamentous mass floating freely on the surface of water forming

bloom (pH 6, temp 10ºC).

Indian distribution: Gujarat (Patel 1979); Bareilly, Uttar Pradesh (Pandey et al.

1987); Nagpur, Maharashtra (Tarar et al. 1998); Gomti river (Kumar & Suseela

2004); Hamirpur, Uttar Pradesh (Habib & Chaturvedi 2007); Uttarakhand (Misra

et al. 2008); Hardoi, Uttar Pradesh (Habib 2009); Kumayun Himalaya (Habib &

Chaturvedi 2011); Dehradun, Uttarakhand (Habib & Chaturvedi 2012).

This is the first report of the taxon from Eastern Himalaya.

47. Closterium rectimarginatum forma

[Pl. XII, f. 283]

Cells medium sized, 6-7 times longer than broad; spindle shaped, straight, 40° of

arc; lateral margins almost straight, slightly convex, elevated, dorsal margin

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slightly more curved than the ventral, attenuated at the apex to form acutely

rounded poles; cell wall smooth and colourless; chloroplast with 4-5 longitudinal

ridges having axial series of several pyrenoids.

Length: 215-219 µm, Breadth: 30-33 µm, Apex: 2-3 µm.

Present taxon differs from the typical having several characters, viz.

1. Cell dimension less

2. Apex acutely rounded.

Collection No. DD-405, 06.11.2009, Changu Lake, Sikkim. In association with

dark green filament on the surface of the water (pH 6, temp. 9ºC).

48. Closterium reticulatum sp. nov.

[Pl. XV, f. 305]

Cells medium sized, 8-9 times longer than broad, almost straight, 26° of arc; both

the margins equally convex in the midregion, then tapering to the poles; apex flat

with rounded angles; cell wall distinctly costate with vertical as well as

horizontal costae forming reticulate patterns; 4-6 prominent vertical costae in

face view, horizontal costae arranged in 5-6 series alternately forming the cell

wall several rectangular areas; cell wall otherwise smooth and colourless;

chloroplast axial plate filling the entire space of the cell.

Length: 297-300 µm, Breadth: 34-36 µm, Apex: 10-13 µm.

Present species resembles Netrium and certain species of Closterium such as Cl.

libellula Focke ex Nordstedt, Cl. costatum Corda ex Ralfs and few others but

distinctively differs from all the above in having vertical as well as transverse

costae forming a reticulate patterns.

Holotype No. DD-417, 06.11.2009, Mamencho Lake, Sikkim. In association

with greenish-brown scum on the surface of the wet rock (pH 6, temp. 10ºC).

Kept in the algae herbarium, Department of Botany, The University of Burdwan

(BURD).

49. Closterium rostratum Ehrenberg ex Ralfs var. rostratum

(West & GS West 1904, p. 188, pl. 26, f. 1-5; Krieger 1937, p. 354, pl. 33, f. 1-3;

Prescott et al. 1975, p. 83, pl. 31, f. 3, 12; Lenzenweger 1996, p. 50, pl. 6, f. 9-10)

[Pl. XXIII, f. 384-386]

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Cells long, 11-12 times longer than broad, slender, slightly curved, 42° of arc;

inflated and fusiform in the midregion, tapering abruptly to form rostrate

extensions in the apical region, the poles obliquely truncate; chloroplast axial

with 3-4 pyrenoids; cell wall smooth and light brown in colour.

Length: 249-297 µm, Breadth: 25-27 µm, Apex: 3-4 µm.

Collection No. DD-415, DD-416, 06.11.2009, Mamencho Lake, Sikkim. In

association with brownish wooly masses and green filaments on the wet surface

of the rocks (pH: 5.5, Temp. 10°C).

Indian distribution: Assam (Brühl & Biswas 1926; Biswas 1934); Kashmir

(Suxena & Venkateswarlu 1968b); Madhya Pradesh (Agarkar 1969; Agarkar &

Agarker 1972; Agarkar & Agarker 1977; Agarkar et al. 1979, Agarkar et al.

1983); Uttar Pradesh (Prasad & Mehrotra 1977b); Bareilly, Uttar Pradesh

(Pandey et al. 1987); Dhunti, Ranchi (Das and Purti 1990).

50. Closterium rostratum Ehrenberg ex Ralfs var. sikkimicum var. nov.

[Pl. XXII, f. 378, 379]

Cells stouter than the typical, 5-6 times longer than broad, slender, little curved,

63° of arc; midregion fusiform, tapering rather abruptly to form rostrate

extensions in the polar regions; apex obliquely truncate with an internal

thickening; cell wall slightly brownish in colour, striated, 8-9 striae in 10 µm;

chloroplast not prominent in this species found.

Length: 236-239 µm, Breadth: 42-45 µm, Apex: 4-5 µm.

Present species differs from typical and all other existing variety by,

1. Much stouter in size

2. Angle of curvature is more.

Holotype No. DD-417, 06.11.2009, Mamencho Lake, Sikkim. In association

with greenish-brown scum on the surface of the wet rock (pH 6, temp 10ºC).

Kept in the algae herbarium, Department of Botany, The University of Burdwan

(BURD).

51. Closterium setaceum Ehrenberg ex Ralfs var. setaceum

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(West & GS West 1904, p. 190, pl. 26, f. 9-13; Krieger 1937, p. 356, pl. 33, f. 8-

10; Prescott et al. 1975, p. 84, pl. 31, f. 1, 11; Lenzenweger 1996, p. 51, pl. 6, f.

8)

[Pl. XXI, f. 370, 371]

Cells long, 22-24 times longer than broad, almost straight, 21° of arc, fusiform in

the midregion, narrowed rather abruptly in the apical region to form rostrate,

colourless extensions with parallel margins; apices incurved which is slightly

inflated, poles truncately rounded; chloroplast with 2 pyrenoids; cell wall

colourless with fine striae, 11 striae in 10 µm.

Length: 408-413 µm, Breadth: 17-18 µm, Apex: 2-3 µm.

Collection No. DD-27, 16.04.2009, Pelling, Sikkim. With phytoplankton

samples collected from a small Lake (pH 5, temp 21ºC). DD-731, 02.05.2010,

Mach pokhri, West Bengal. With phytoplankton sample collected from the water

body (pH 6, temp. 22ºC).

Indian distribution: Eastern India (Turner 1892); Vidarbh, Maharashtra (Kamat

1975); Savandurga, Karnataka (Gurudeva et al. 1983); Bareilly, Uttar Pradesh

(Pandey & Habib 1987); Rohilkhand, Uttar Pradesh (Habib 1993); Pilibhit, Uttar

Pradesh (Habib 1997); Orissa (Jena et al. 2006); Ranchi (Guru 2007); Kolhapur,

Maharashtra (Leela et al. 2012).

This is the first report of the taxon from Eastern Himalaya.

52. Closterium sikkimicum sp. nov.

[Pl. XXII, f. 380, 381]

Cells large, 18-20 times longer than broad, slender, almost straight, curvature is

much less, 37° of arc; lateral margins parallel and straight for more than one half

of the length then gradually attenuated toward the poles, apex truncate with

rounded angles; cell wall smooth and colourless; girdle bands present;

chloroplast with numerous pyrenoids in a series.

Length: 675-678 µm, Breadth: 34-36 µm, Apex: 13-16 µm.

Present specimen is intermediate between Cl. gracile Brébisson ex Ralfs & Cl.

abruptum West but differs from both in several respects. viz.

From Cl. gracile Brébisson ex Ralfs by

1. Dimension is much greater

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2. Less slender, Length/Breadth ratio less.

From Cl. abruptum West by,

1. Angle of curvature is less

2. Cell dimension is much greater

3. More slender i.e. L/B ratio greater.

Holotype No. DD-396, 06.11.2009, Babamandir, Sikkim. In association with

scum with mosses on the rock under the stream. Kept in the algae herbarium,

Department of Botany, The University of Burdwan (BURD).

53. Closterium striolatum Ehrenberg ex Ralfs var. erectum Klebs

(Krieger 1937, p. 339, pl. 28, f. 12; Prescott et al. 1975, p. 88, pl. 27, f. 4, 8)

[Pl. XI, f. 276, 277]

Cells long, 8-13 times longer than broad, slightly curved, 44° of arc; ventral

margin straight in greater part of the length then slightly curved to the poles,

dorsal margin slightly convex, gradually attenuated to the apex, apex broadly

truncate, somewhat angularly incurved; cell wall slightly yellowish in colour and

striated, 6-7 striae in 10 µm; girdle bands present; chloroplast with 9 longitudinal

ridges and 6-7 pyrenoids in series.

Length: 378-407 µm, Breadth: 29-31 µm, Apex: 7-8 µm.

Collection No. DD-420, 06.11.2009, Mamencho Lake, Sikkim. In association

with light green filaments on the surface of the water (pH 6, temp 10ºC).

Indian distribution: This is probably the first report of the taxon from India.

54. Closterium striolatum Ehrenberg ex Ralfs var. subdirectum (West) Krieger

(Prescott et al. 1975, p. 89, pl. 27, f. 2, 13)

[Pl. XXIII, f. 387]

Cells large, slender, 12-14 times longer than broad, slightly curved, curvature 46°

of arc; midregion with margins slightly inflated, gradually attenuated toward the

apical region which is somewhat incurved; the poles broadly rounded; cell wall

yellowish-brown in colour, striated, 9 striae in 10 µm; girdle bands evident.

Length: 431-438 µm. Breadth: 31-34 µm. Apex: 13-16 µm.

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Collection No. DD-129, 18.04.2009, Khechiperi Lake, Sikkim. In association

with green filaments growing attached on pebbles & submerged weeds (pH 6.5,

Temp. 14°C).

Indian distribution: This is probably the first report of the taxon from India.

55. Closterium striolatum Ehrenberg ex Ralfs var. subtruncatum (West et GS West)

Krieger

(Krieger 1937, p. 340, pl. 28, f. 10; Prescott et al. 1975, p. 89, pl. 27, f. 7;)

[Pl. XIV, f. 292, 293]

Cells elongate, 8-9 times longer than broad, slightly curved having 50-60° of arc,

the midregion with margins slightly inflated, gradually attenuated toward the

apical region which is somewhat incurved; apices slightly swollen, especially on

the dorsal wall, giving the cell a compressed appearance below the apices; cell

wall brownish with striations, 9-10 striae in 10 µm.

Length: 405-420 µm, Breadth: 46-50 µm, Apex: 10-11 µm.

Collection No. DD-417, 06.11.2009, Mamencho Lake, Sikkim. In association

with greenish-brown scum on the surface of the wet rock (pH 6, temp 10ºC).

Indian distribution: Karnataka (Isaacs & Hegde 1987); Kollam, Kerala

(Panikkar & Krishnan 2005); Mamencho Lake (Das & Keshri 2012).

56. Closterium subcosticum Gutwinski

(Krieger 1937, p. 333, pl. 27, f. 10-12; Lenzenweger 1996, p. 53, pl. 4, f. 11)

[Pl. XIII, f. 290, 291]

Cells of medium sized, 9-11 times longer than broad, very slightly curved, 20° of

arc; dorsal margin slightly convex, ventral margins more or less straight,

attenuated to the apex forming rounded poles; girdle bands present, cell wall with

fine striations, 6-7 striations in 10 µm; chloroplast axial plate with 4-6 pyrenoids

in series.

Length: 161-164 µm, Breadth: 15-17 µm, Apex: 4-6 µm.

Collection No. DD-417, 06.11.2009, Mamencho Lake, Sikkim. In association

with greenish-brown scum on the surface of the wet rock (pH 6, temp 10ºC).

Indian distribution: This is probably the first report of the taxon from India.

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57. Closterium subfusiforme Messikommer

(Prescott et al. 1975, p. 89, pl. 14, f. 9-11; Lenzenweger 1996, p. 52, pl. 4, f. 4)

[Pl. XX, f. 361, 362]

Cells medium sized, 6-7 times longer than broad, straight, 32° of arc, fusiform,

nearly equally curved on each margin, gradually tapered to truncate poles;

chloroplast with 4 longitudinal ridges having several pyrenoids in a series; cell

wall smooth and colourless.

Length: 175-178 µm, Breadth: 26-27 µm, Apex: 3-4 µm.

Collection No. DD-413 06.11.2009, Mamencho Lake, Sikkim. In association

with green filaments attached on the surface of the partially submerged rocks (pH

6, temp 10ºC). DD-17, 16.04.2009, Pelling, Sikkim. In association with slimy

deep green filaments on the margin of a water body (pH 5, temp 19ºC).

Indian distribution: This is probably the first report of the taxon from India.

58. Closterium subjuncidiforme Gronblad

(Krieger 1937, p. 362, pl. 34, f. 10; Prescott et al. 1975, p. 90, pl. 29, f. 3, 3a, 3b)

[Pl. XI, f. 278, 279; pl. XII, F. 280-282]

Cells large, 10-11 times longer than broad, very slightly curved, 17° of arc,

slightly narrowed toward the apical region; the poles truncately rounded; cell

wall with girdle bands, brownish in colour, striated, 3 striae in 10 µm which is

sometimes spirally disposed.

Length: 362-455µm, Breadth: 20-41 µm, Apex: 6-21 µm.

Collection No. DD-382, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with green filamentous mass attached to the surface of the submerged aquatic

plants (pH 6, temp 10ºC). DD-396, 06.11.2009, Babamandir, Sikkim. In

association with mosses on the rocks under the stream (pH 6, temp. 10ºC). DD-

584, 12.11.2009, Namchi, Sikkim. In association with greenish scum with wet

mosses growing on soil (pH 6.5, temp. 15ºC).

Indian distribution: This is probably the first report of the taxon from India.

59. Closterium tacomense Prescott

(Prescott et al. 1975, p. 91, pl. 19, f. 6, 9)

[Pl. XVII, f. 328, 329]

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Cells medium sized, 7-9 times longer than broad, strongly curved, 152° of arc,

lunate; dorsal margin more curved than the ventral, very slightly tumid at the

midregion abruptly attenuated to the apical region to narrowly rounded poles; cell

wall smooth, colour reddish-brown; girdle bands present in the midregion;

chloroplast axial with 3 pyrenoids.

Length: 98-104 µm, Breadth: 11-14 µm, Apex: 4-5 µm.

Our species is much smaller in dimension than the type.

Collection No. DD-420, 06.11.2009, Mamencho Lake, Sikkim. In association

with green filaments on the surface of the water (pH 6, temp. 10ºC).

Indian distribution: This is probably the first report of the taxon from India.

60. Closterium tumidulum Gay

(Prescott et al. 1975, p. 92, pl. 36, f. 1, 10; Lenzenweger 1996, p. 53, pl. 3, f. 18)

[Pl. XVIII, f. 346, 347]

Cells medium sized, 6-7 times longer than broad, strongly curved with 140°-

150° of arc; the dorsal wall strongly curved, the ventral margin inflated in the

midregion; poles acutely rounded; wall smooth, colourless; chloroplasts 2-3 with

longitudinal ridges with 2 pyrenoids in each placed in series.

Length: 120-149 µm, Breadth: 22-28 µm, Apex: 3-5 µm.

Collection No. DD-387, 06.11.2009, Betang-cho Lake, Sikkim. In association

with light green filaments floating freely on the surface of the water (pH 6, temp.

10ºC).

Indian distribution: Eastern India (Turner 1892); Andhra Pradesh (Suxena &

Venkateswarlu 1968a); Nainital (Kamat 1973a); Vidarbh, Maharashtra (Kamat

1975); Madhya Pradesh (Agarkar & Agarkar 1977); Savandurga, Karnataka

(Gurudeva et al. 1983); River Cauvery (Somashekar 1984); Bareilly, Uttar

Pradesh (Pandey et al. 1987); Tamil Nadu (Senthilkumar & Sivakumar 2008);

Bihar (Kumar & Chaudhary 2009).

This is the first report of the taxon from Eastern Himalaya.

61. Closterium tumidulum Gay forma

[Pl. XVI, f. 316, 317]

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Cells medium sized, 7-9 times longer than broad, strongly curved, 156° of arc;

dorsal margins strongly convex, ventral margin with midregion very slightly

tumid, gradually attenuated to the apex forming rounded poles; cell wall smooth

and colourless; chloroplasts with 4 longitudinal ridges.

Length: 120-127 µm, Breadth: 14-17 µm, Apex: 3-5 µm.

Present species differs from the typical by,

1. Ventral margins less tumid

2. Poles rounded

3. Terminal vacuoles absent.

Collection No. DD-379, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with deep green filamentous mass floating freely on the surface of water forming

bloom (pH 6, temp. 10ºC).

62. Closterium venus Kutzing ex Ralfs

(West & GS West 1904, p. 137, pl. 15, f. 15-20; Krieger 1937, p. 272, pl. 16, f. 1-

5; Prescott et al. 1975, p. 96, pl. 24, f. 5, 12; Lenzenweger 1996, p. 54, pl. 2, f.

25)

[Pl. XXI, f. 372, 373]

Cells small, 7-9 times longer than broad, strongly curved, 168° of arc; both the

dorsal and ventral margins strongly curved, not inflated in the midregion,

gradually attenuated towards the apex, apex acutely rounded; cell wall smooth

and colourless; chloroplast axial.

Length: 51-53 µm, Breadth: 6-7 µm, Apex: 1-2 µm.

Collection No. DD-31, 16.04.2009, Pelling, Sikkim. In association with blackish

mass on the rocky surface of the wall. DD-631, 04.05.2010, Gurudongmar Lake,

Sikkim. With phytoplankton sample collected from the Lake (pH 6, temp 9ºC).

Indian distribution: Eastern India (Turner 1892); Assam (Brühl & Biswas

1926); Andhra Pradesh (Suxena & Venkateswarlu 1966b); Simla (Kamat 1968b);

Gujarat (Patel 1969); Madhya Pradesh (Agarkar 1969; Agarkar & Agarker 1973);

Nainital (Kamat 1973a); Vidarbh, Maharashtra (Kamat 1975); Gujarat (Patel

1979); Allahabad, Uttar Pradesh (Pandey & Pandey 1980); Karnataka and Goa

(Bharti & Hegde 1982a); Bareilly, Uttar Pradesh (Pandey et al. 1987); Kerala

(Shaji et al. 1988); Bombay, Maharashtra (Schmidle 1990; Gonzalves & Joshi

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1946; Kamat 1963, 1968); Pithoragarh (Chaturvedi & Habib 1993); Nagpur,

Maharashtra (Tarar et al. 1998); Shillong, Meghalaya (Gupta 2002); Ranchi

(Guru 2007); Hamirpur, Uttar Pradesh (Habib & Chaturvedi 2007); Sitapur, Uttar

Pradesh (Habib 2008a); Uttarakhand (Misra et al. 2008); Hardoi, Uttar Pradesh

(Habib 2009); Kumayun Himalaya (Habib & Chaturvedi 2011); Dehradun,

Uttarakhand (Habib & Chaturvedi 2012).

This is a fairly common species of Closterium in India.

63. Closterium venus Kutzing ex Ralfs var. venus f. minor Roll

(Prescott et al. 1975, p. 96, pl. 24, f. 16)

[Pl. XXI, f. 374, 375]

Cells small, 6-7 times longer than broad, strongly curved, 142° of arc; the dorsal

margin convex, ventral wall slightly more curved, concave, gradually attenuated

toward the apical region, poles acutely rounded; chloroplast axial with 2

pyrenoids in each; cell wall colourless and smooth.

Length: 34-37 µm, Breadth: 5-6 µm, Apex: 1-2 µm.

No. DD-583, 12.11.2009, Namchi, Sikkim. In association with greenish-brown

scum with mosses on a small rock pool (pH 6.5, temp. 14ºC).

Indian distribution: This is probably the first report of the taxon from India.

64. Closterium venus Kutzing var. crassum Croasdale

(Prescott et al. 1975, p. 97, pl. 24, f. 15)

[Pl. XIV, f. 301]

Cells moderate in size than the typical, 6-8 times longer than broad, slightly

stouter and strongly curved, 177° of arc; both the ventral and dorsal margins are

equally curved; apex attenuated; cell wall smooth and colourless; chloroplast

axial with single median pyrenoids.

Length: 70-73 µm, Breadth: 9-11 µm, Apex: 2-3 µm.

Collection No. DD-417, 06.11.2009, Mamencho Lake, Sikkim. In association

with greenish-brown scum on the surface of the wet rock (pH 6, temp. 10ºC).

Indian distribution: Bareilly, Uttar Pradesh (Pandey et al. 1988); Lakhimpur-

Kheri, Uttar Pradesh (Habib 1995).

This is the first report of the taxon from Eastern Himalaya.

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IV. Cosmarium Corda ex Ralfs

Cells solitary, small to large in size, elongate, circular, semicircular, sub-semicircular

ellipsoidal, rectangular, elongate-circular or elongate-semicircular in shape in face

view, circular, oval or elliptic in vertical view; cells with shallow to deep median

constriction or sinus at the isthmus region; sinus may be deep or shallow, closed,

linear or open that may be angularly or widely dilated; semicells variously shaped,

that may be circular, semicircular, sub-semicircular, ellipsoidal, elliptic-reniform,

transversely elliptic, obliquely elliptical, rectangular, quadrangular, trapiziform,

pentagonal, hexagonal, elongate-circular or elongate-semicircular, cylindrical, sub-

cylindrical, elongate-cylindric, pyramidal, sub-pyramidal etc.; lateral margins may be

entire, undulate, crenulate, papillate, verrucate or conical teethed; cell wall may be

smooth or punctate, sometimes granulate, scrobiculate or verrucate; wall ornamented

either entirely or to restricted parts; cell apex may be broad or narrow, rounded, flat,

retuse or convex; face of the semicells smooth or variously ornamented, one or two

median protrusions may be present, sometimes with several types of thickenings or

granules arranged in various pattern; chloroplast axial, sometimes with longitudinal

ridges or radiating lobes, single or double in each semicells with one or two

pyrenoids; nucleus single, present at the middle portion of the cell.

Key to the taxa investigated:

For convenience the investigated taxa have been grouped into following groups:

A. Semicells circular or semicircular or sub-semicircular in outline

B. Semicells cylindrical, elongate-cylindrical or sub-cylindrical in outline

C. Semicells pyramidal or sub-pyramidal in outline

D. Semicells transversely or obliquely elliptical or reniform

E. Semicells rectangular, sub-rectangular, trapiziform or quadrangular in outline

F. Semicells hexagonal or polygonal in outline

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A. Semicells circular or semicircular or sub-semicircular in outline

1. Cell wall smooth or punctate, not granulate, margins may be undulate

2. Semicells circular in outline

3. Median constriction deep, isthmus at least half or less than that of maximum

width of the cell

4. Cell small, 17-19 µm in length……...…………………….(35) C. moniliforme

4. Cells relatively larger, 60-63 µm in length..……….(36) C. moniliforme forma

3. Median constriction rather shallow, isthmus about one tenth than that of

maximum width of the cell

5. Semicells sub-circular in outline…….……..…(7) C. connatum var. connatum

5. Semicells transversely more elliptic…..……..(8) C. connatum var. depressum

2. Semicells semi-circular or sub-semicircular in outline

6. Outer margin of the semicells entire

7. Basal angles with sub-mamillate thickening

8. Apex thickened, wall smooth………………………….…...…(40) C. nudum

8. Apex not thickened, wall punctate

9. Sinus deep, closed, pores irregular……...………………(41) C. obsoletum

9. Sinus shallow, widely open, pores in vertical rows

…...…(54) C. pseudo-obsoletum sp. nov.

7. Basal angles without any thickenings, smooth

10. Semicells semicircular-cylindrical, cells more than 1.5 times longer than

broad……………………………………………………(68) C. subcucumis

10. Semicells semicircular or very slightly elongate, cells less than 1.5 times

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longer than broad

11. Sinus dilate at the extremities, pores distinct

………….(33) C. lundelli var. ellipticum

11. Sinus not dilated, finely porous…..………..……….(73) C. transitorium

6. Outer margin of the semicells undulate

12. Cells large in size, length more than 50 µm. long, isthmus very deep, about

1/5th

than the maximum width of the cell…...….………..…(75) C. tyloricum

12. Cells relatively smaller, length less than 50 µm. long, isthmus not very deep,

about 1/2- 1/3 than the maximum width of the cell

13. Cells slightly elongate, about 1.5 times longer than broad, undulations

distinct…………………....(76) C. undulatum var. alaskanum f. reductum

13. Cells not elongate, about 1.2 times longer than broad, undulations faint

14. Semicells more than 30 µm. long, undulations 18-20 per semicells

…………...(79) C. undulatum var. wollei

14. Semicells less than 30 µm. long, undulations 9-10 per semicells

….…….(78) C. undulatum var. minutum

1. Cell wall granulate, verrucate, papillate or crenulate at the margins or on the face of

the semicells

15. Semicels circular in outline……………………………(47) C. portianum forma

15. Semicells of other shape, either semicircular or sub-semicircular

16. Apex broadly truncate

17. Lateral walls with sharp granules…...……………..(67) C. subcrenatum

17. Lateral walls with undulations

18. Cell dimension large, more than 50 µm. long, another series of

undulations just below the apex, face of the semicells smooth

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…………..(11) C. cyclicum var. crassum

18. Cell dimension small, less than 50 µm. long, face of the semicells

with concentric series of undulations…………….…(80) C.vittanum

16. Apex broadly rounded

19. Semicells semicircular-elliptic, sinus shallow, open, cell wall covered

with wooly hairs………..…...……………...(65) C. sikkimicum sp. nov.

19. Semicells semicircular, sinus deep, closed, cell wall with either teeth or

undulations, not hairs

20. Lateral walls with undulations

…...(77) C. undulatum var. indicum var. nov.

20. Lateral walls with teeth or crenulations

21. Lateral walls with broad crenations, face of the semicells with

specialized thickenings…………….……..…(10) C. cycladatum

21. Lateral walls with short teeth, face os the semicells without any

thickenings, smooth………………....(81) C. yoksomum sp. nov.

B. Semicells cylindrical, elongate-cylindrical or subcylindrical in outline:

1. Cell wall smooth or punctate, not granulate

2. Isthmus shallow with notched extremities, apex flat with rounded angles, wall

smooth………………...…………(32) C. longicylindricum var. indicum var. nov.

2. Isthmus deeper with dilate extremities, apex broadly rounded, cell wall porous

...………..(51) C. pseudodebaryi sp. nov.

1. Cell wall granulate

3. Median constriction a linear ‘V’ shaped notch…(1) C. amoenum var. intumescens

3. Median constriction very shallow

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4. Cells narrow, slender, more than 2.5 times longer than broad

………………….(49) C. pseudamoenum

4. Cells relatively broad and stout, less than 2.5 times longer than broad

…(6) C. cohnii (Nob.) Keshri et Das comb. nov.

C. Semicells pyramidal or sub-pyramidal in outline:

1. Cell wall smooth or punctate, margins may be undulate but not granulate or crenate

2. Cell wall smooth, not punctate

3. Margins of the semicells undulate

4. Entire margin of the semicells undulate including the apex

5. Sinus deep, closed, cells stout, less than 1.3 times longer than broad

…………………….(38) C. naegelianum

5. Sinus shallow, open notch, slightly longer, more than 1.3 times longer than

broad………………………………….……………….…(31) C. levinotabile

4. Apex not undulate, may be retuse or flat

6. Apex flat

7. Cell dimension small, sinus not dilated at the apex

…….(19) C. garrolense f. dimidio-minus

7. Cells slightly longer, sinus dilated at the apex……..…..(18) C. garrolense

6. Apex retuse

8. Cells broader, less than 1.3 times longer than broad

…………...(20) C. garrolense var. minus

8. Cells relatively larger, more than 1.3 times longer than broad

9. Lateral margins of the semicells nearly straight at the lower part, then

attenuate to the apex…….....…….(27) C. impressulum var. impressulum

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9. Lateral margins of the semicells not straight rather convex, then

attenuate to the apex……...…(28) C. impressulum var. suborthrogonum

3. Margin of the semicells entire, not undulate

10. Lateral walls straight or rarely slightly convex

11. Apex flat, basal angles narrowly rounded, sinus open..…(39) C. nitidulum

11. Apex broadly rounded, basal angles broad, sinus closed

………...(53) C. pseudolundellii sp. nov.

10. Lateral walls not straight

12. Apex retuse

13. Semicells with 2 pyrenoids, cells greater than 50 µm

…..(2) C. angulatum var. angulatum f. major

13. Semicells with single pyrenoid, length less than 50 µm

…..…(23) C. granatum var. subangulare

12. Apex flat, not retuse

14. Cell apex broad, more than half the maximum breadth of the cell, cell

more than 30 µm long………..…….(25) C. hammeri var. protuberans

14. Cell apex narrower, less than half the maximum breadth of the cell,

cell less than 30 µm long

15. Apical lateral angles sharply pointed

16. Cells larger, more than 25 µm long

………….(24) C. hammeri var. hammeri

16. Cells smaller, less than 25 µm long….……..…(63) C.retusiforme

15. Apical lateral angles rounded

17. Lateral walls almost straight, very slightly retuse, apex narrow

………………...…...…(21) C. granatum

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17. Lateral walls distinctly concave, apex broader

………...(26) C. hammeri var. schmedlei

2. Cell wall punctate

18. Apex flat or retuse

19. Cells small, length less than 50 µm.

20. Apex narrow, lateral walls convex

21. Apex retuse, pores minute……….…….(30) C. laeve var. octangulare

21. Apex flat, pores large……………….(22) C. granatum var. elongatum

20. Apex broad, upper portion of lateral walls retuse…...(74) C. trilobulatum

19. Cells large, length more than 50 µm.

22. Sinus shallow, open………...(56) C. pyramidatum var. indicum var. nov.

22. Sinus deep, closed

23. Lateral walls smooth, sinus not dilated

….….(17) C. galeritum var. subtumidum

23. Lateral walls undulate, sinus dilated…...……...(12) C. cymatopleurum

18. Apex broadly rounded

24. Cells longer, above 1.5 times longer than broad, length more than 100 µm

25. Highest breadth at the base of the semicells, pores minute

……………………(43) C. pakistanicum

25. Highest breadth just above the base of the semicells, pores larger

……...……………......(29) C. javanicum

24. Cells relatively smaller, below 1.5 times longer than broad, length less than

100 µm

26. Isthmus deep, about 1/3 times than the maximum breadth of the cell,

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sinus closed but open outwardly, punctae irregular…(71) C. subtumidum

26. Isthmus shallow, less than 1/3 times than the maximum breadth of the

cell, sinus entirely closed, punctae arranged in concentric manner

………….…(55) C. pseudopyramidatum

1. Cell wall granulate, verrucate, papillate or crenulate at the margins or on the face of

the semicells

27. Sinus open……….....………………...(42) C. ornatum var. sikkimicum var. nov.

27. Sinus closed

28. Outer margins undulate with 2 series of undulation just below the apex, face

of the semicells with a ring of granules……..(50) C. pseudocyclicum sp. nov.

28. Outer margins with teeth, median portion of the face of semicells smooth

…….........(4) C. botrytis var. mediolaeve

D. Semicells transversely or obliquely elliptical or reniform:

1. Semicells reniform or obliquely reniform in outline

2. Cell wall smooth or punctate, not granulate

3. Semicells with one or two median protuberance in face view

4. Semicells with one protuberance in face view

5. Cells smaller, less than 30 µm. long, semicells slightly compressed

…..…..………(45) C. phaseolus f. minus

5. Cells slightly longer, more than 30 µm. long, semicells not compressed

…..……(44) C. phaseolus var. phaseolus

4. Semicells with 2 protuberances in face view

……….(69) C. subphaseolanum sp. nov.

3. Semicells without any median protuberance

6. Semicells as long as broad or slightly broader, sinus closed

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……………………(37) C. montrealense

6. Semicells longer than broad, sinus open angularly

……….(14) C. depressum var. reniforme

2. Cell wall granulate, verrucate, papillate or crenulate at the margins or on the face

of the semicells

7. Sinus closed

8. Sinus deep, more than 1/3 times than the maximum breadth of the cell

…...……….(62) C. reniforme var. minor

8. Sinus shallow, about 1/2 times than the maximum breadth of the cell

…...…………………..……(64) C. rosae

7. Sinus open

10. Cell dimension larger, more than 25 µm long, apex of the sinus rounded

……(48) C. portianum var. nephroideum

10. Cell dimension smaller, less than 25 µm long, apex of the sinus angular

…...….(46) C. portianum var. portianum

1. Semicells transversely elliptical or oblong-elliptical

11. Semicells flatly compressed, sinus closed

…..(15) C. dorsitruncatum var. pseudoscenedesmus

11. Semicells not flatly compressed, sinus open

12. Basal angles acutely rounded..……………………..……..(72) C. tithophorum

12. Basal angles broadly rounded

13. Cells stout, as broad as long…..…………….(13) C. depressum f. minutum

13. Cells relatively elongate, 1.2-1.3 times longer than broad

……...…(9) C. contractum var. minutum

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E. Semicells rectangular, sub-rectangular, trapiziform or quadrangular in

outline:

1. Cell wall smooth or punctate

2. Cells small, length less than 50 µm

3. Sinus closed throughout, semicells transversely rectangular

…......(34) C. minimum var. subrotundum

3. Sinus ‘V’ shaped notch, semicells quadrangular………………(5) C. coaractum

2. Cells large, length greater than 50 µm

4. Lateral margins somewhat convex

5. Cells stout, broader, less than 1.5 times longer than broad, apex broadly

rounded………………………………….….…...(60) C. quadratum var. willei

5. Cells slightly elongate, 1.5 times or more longer than broad, apex rounded

…………(59) C. quadratum var. boreale

4. Lateral margins straight or somewhat retuse

6. Cell wall punctate, sinus angularly open, apex without any thickening

…..……………….(70) C. subquadratum

6. Cell wall smooth, sinus shallow notch, apex with a button-like thickening

…..……………...(52) C. pseudoexiguum

1. Cell wall granulate, verrucate or papillate at the margins or on the face of the

semicells

7. Semicells small, trapiziform, sinus open, broad, ‘U’-shaped………(61) C. regnesi

7. Semicells relatively large, transversely rectangular, sinus closed

8. Apex broadly concave, granules large..…...(16) C. favum var. indicum var. nov.

8. Apex retuse, granules relatively small

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9. Cell dimension small, length less than 50 µm……(58) C. quadrum var. minus

9. Cell dimension larger, length more than 50 µm

………….(57) C. quadrum var. quadrum

F. Semicells hexagonal or polygonal in outline:

1. Lateral margins of the semicell with a tubercle, apex retuse…...…(66) C. sinostigos

1. Lateral margins of the semicell without a tubercle only angularly convex, apex flat

…………...……………(3) C. baffinense

1. Cosmarium amoenum (Brébisson) Ralfs var. intumescens Nordstedt

(Prescott et al. 1981, p. 65, pl. 287, f. 2; Lenzenweger 1999, p. 108, pl. 60, f. 5, 6)

[Pl. V, f. 129]

Cells large, 1.5-2 times longer than broad; median constriction moderate, the sinus

slightly open and acute angled; semicells more or less cylindrical, rounded-

quadrate with lateral margins and apex convexly rounded; cell walls granulate,

granules more or less in vertical series, 7 vertical series of granules present in face

view, granules at the base of the semicells, more or less irregularly disposed in

vertical series; chloroplast axial with 2 pyrenoids in each semicells.

Length: 80-82 µm, Breadth: 44-46 µm, Isthmus: 28-29 µm.

Collection No. DD-197, 19.04.2009, Yoksum, Sikkim. In association with

blackish mass in a swamp near a falls (pH 5.5, temp. 19ºC).

Indian distribution: This is probably the first report of the taxon from India.

2. Cosmarium angulatum (Perty) Rabenhorst f. major (Grunow) Turner

(Turner 1892, p. 56, pl. 8 f. 35, pl. 9, f. 25; Prescott et al. 1981, p. 69, pl. 204, f. 8,

11, pl. 205, f. 12)

[Pl. III, f. 82-84]

Cells medium sized, 1.4-2 times longer than broad; median constriction deep,

isthmus narrow; sinus closed; semicells 6-angled, basal angles rounded, the lateral

margins little convex above the basal angles and broadly rounded upper, lateral

angles, then converging and retuse to a narrow, truncate apex which is also retuse;

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face of the semicells smooth; chloroplast two in each semicells with two

pyrenoids.

Length: 49-69 µm, Breadth: 27-46 µm, Isthmus: 16-22 µm.

Collection No. DD-389, 06.11.09, Bitang-cho Lake, Sikkim. In association with

light green filaments on the surface of the water (pH 6, temp. 10ºC). DD-583,

12.11.2009, Namchi, Sikkim. In association with greenish-brown scum with

mosses on a small rock pool (pH 6.5, temp. 14ºC). DD-724, 02.05.2010,

Kalimpong. In association with brown scum with wet mosses beside a drain (pH

6.5, temp. 24ºC).

Indian distribution: Eastern India (Turner 1892); Allahabad (Pandey & Pandey

1980); Pithoragarh (Chaturvedi & Habib 1993); Uttarakhand (Misra et al. 2008).

This is the first report of the taxon from Eastern Himalaya.

3. Cosmarium baffinense Whelden

(Prescott et al. 1981, p. 77, pl. 172, f. 12; pl. 213, f. 2-4)

[Pl. VI, f. 189, 190]

Cells small, as long as broad; semicells hexagonal with rounded angles; median

constriction deep, sinus closed, linear; lateral walls angularly concave; apex broad

and flat; cell wall minutely punctate.

Length: 10-11 µm, Breadth: 10-11 µm, Isthmus: 4-5 µm.

Collection No. DD-584, 12.11.2009, Namchi, Sikkim. In association with

greenish scum with wet mosses growing on soil (pH 6.5, temp. 15ºC).

Indian distribution: This is probably the first report of the taxon from India.

4. Cosmarium botrytis (Meneghini) Ralfs var. mediolaeve West

(West & GS West 1912, p. 6. pl. 97, f. 5; Prescott et al. 1981, p. 90, pl. 265, f. 3;

Lenzenweger 1999, p. 111, pl. 56, f. 3)

[Pl. V, f. 130]

Cells large, 1.2-1.3 times longer than broad, median constriction deep, sinus

narrowly linear; semicells ovate-pyramidal, lower angles rounded, lateral margins

convex, apex truncate, upper angles rounded; cell wall uniformly granulate except

the apex; granules arranged in radiating and in concentric series, gradually

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becoming smaller toward the midregion of the semicell which is quiet smooth;

granules somewhat small and generally without any definite disposition.

Length: 57-59 µm, Breadth: 47-49 µm, Isthmus: 23-25 µm.

In our specimen extremities are not dilated.

Collection No. DD-500, 10.11.2009, Changey falls, Sikkim. In association with

greenish scum on wet rock beside the falls (pH 6, temp. 14ºC).

Indian distribution: Gangtok, Sikkim (Prasad & Misra 1987); Southern

Himachal Pradesh (Dwivedi et al. 2009).

5. Cosmarium coarctatum West

(West & GS West 1908, p. 69, pl. 71, f. 8; Prescott et al. 1981, p. 101, pl. 205, f.

4, 5)

[Pl. VI, f. 181, 182]

Cells small, slightly longer than broad, median constriction shallow, the sinus

open, ‘V’-shaped notch; semicells rectangular, basal angles rounded, lateral

margins nearly parallel to a flat, truncate apex; cell wall smooth.

Length: 13-15 µm, Breadth: 10-12 µm, Isthmus: 4-6 µm.

Collection No. DD-583, 12.11.2009, Namchi, Sikkim. In association with

greenish-brown scum with mosses on a small rock pool (pH 6.5, temp. 14ºC).

Indian distribution: This is probably the first report of the taxon from India.

6. Cosmarium cohnii (Nobilis) Keshri et Das comb. nov.

[Basionym Dysphinctium cohnii (Kirchner) Nobilis in Turner 1892, p. 41, pl. 8, f.

39]

[Pl. V, f. 125, 126]

Cells large, elongate, cylindrical, about 1.5 times longer than broad; median

constriction shallow, sinus widely open notch; semicells sub-cylindrical; lateral

margins evenly convex, slightly tumid to the apex which is broadly rounded; cell

wall verrucate, verrucae large, granular, closely arranged, numerous; face of the

semicells with similar concentric large granules all over the body.

Length: 93-96 µm, Breadth: 59-61 µm, Isthmus: 51-52 µm.

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Since Dysphinctium is an invalid genus and all the members under this genus have

been transferred to either Actinotaenium or Cosmarium. The taxon has therefore

been placed under Cosmarium.

Collection No. DD-389, 06.11.09, Bitang-cho Lake, Sikkim. In association with

light green filaments on the surface of the water (pH 6, temp. 10ºC).

7. Cosmarium connatum (Brébisson) Ralfs var. connatum

(West & GS West 1908, p. 25, pl. 66, f. 15-17; Prescott et al. 1981, p. 102, pl.

202, f. 8, 9, 12, 13)

[Pl. V, f. 127, 128]

Cells large, 1.2-1.5 times longer than broad; median constriction shallow, the

sinus very widely open; semicells transversely sub-elliptic, with a broad base,

apex very slightly flattened; cell wall finely punctate; chloroplast disposed in

relation to 2 large pyrenoids in each semicell and extending to the inner surface of

the cell wall.

Length: 57-61 µm, Breadth: 36-42 µm, Isthmus: 30-35 µm.

Collection No. DD-194, 19.04.2009, Yoksum, Sikkim. In association with green

filaments in a swamp (pH 5.5, temp. 19ºC). DD-488, 09.11.2009, Khechiperi

Lake, Sikkim. In association with blackish mass with weeds (Potamogeton sp.)

lodged on roots (pH 6, temp. 10ºC).

Indian distribution: East India (Turner 1892); Bombay and Karnatak (Bharati

1966); Vidarbh, Maharashtra (Kamat 1975); Madhya Pradesh (Agarkar & Agarkar

1977, Agarkar et al. 1979); Uttar Pradesh (Prasad & Mehrotra 1977b); Nagpur

(Freitas & Kamat 1980); Allahabad (Pandey & Pandey 1980); Gujarat (Kumar &

Patel 1988); Bareilly, Uttar Pradesh (Pandey et al. 1988); Rohilakhand, Uttar

Pradesh (Habib 1993); West Bengal (Mukherjee & Srivastava 1993); Kerala

(Sindhu & Panikkar 1995a); Nagpur, Maharashtra (Tarar et al. 1998); Kalimpong,

Namchi, Nayabazar, Phalut (Santra & Pal 2006); Jalgaon, North Maharashtra

(Mahajan & Nandan 2008); Jashpur, Chattisgarh (Toppo & Suseela 2009);

Jalgaon, Maharashtra (Patil et al. 2012).

This is a fairly common taxon of Cosmarium in India.

8. Cosmarium connatum (Brébisson) Ralfs var. depressum Irénée-Marie

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(Prescott et al. 1981, p. 103, pl. 202, f. 11)

[Pl. V, f. 145]

Cells large, 1.4-1.5 times longer than broad; median constriction moderate but

deeper than the typical, the sinus widely open; semicells transversely more elliptic

than the typical one, with a broad basal region; apex broadly rounded; inner wall

at the apex slightly retuse downwards; cell wall punctate, punctae large, arranged

in regular vertical series; chloroplast disposed in relation to 2 large pyrenoids in

each semicell and extending to the inner surface of the cell wall.

Length: 59-60 µm, Breadth: 41-42 µm, Isthmus: 32-33 µm.

Collection No. DD-536, 10.11.2009, Sordum, Sikkim. In association with green

scum on the wet rock (pH 6, temp. 10ºC).

Indian distribution: Allahabad (Pandey & Pandey 1980); Lakhimpur-Kheri,

Uttar Pradesh (Habib 1995).

This is the first report of the taxon from Eastern Himalaya.

9. Cosmarium contractum Kirchner var. minutum (Delponte) West et GS West

(West & GS West 1905, p. 173, pl. 61, f. 30-33; Prescott et al. 1981, p. 108, pl.

175, f. 16, 17 Lenzenweger 1999, p. 41, pl. 50, f. 20-22)

[Pl. IV, f. 107-110]

Cells moderately small, 1.2-1.3 times longer than broad, median constriction deep,

sinus widely open from a sharp-angled interior; semicells elliptic with broadly

rounded apex; chloroplast axial with single median pyrenoid; cell wall smooth.

Length: 26-28 µm, Breadth: 20-23 µm, Isthmus: 7-9 µm.

No. DD-379, 06.11.09, Bitang-cho Lake, Sikkim. In association with deep green

filaments floating freely on the surface of water forming bloom (pH 6, temp.

10ºC). DD-792, 11.11.2011, Rishop, West Bengal. In association with reddish

yellow powdery mass with the mosses growing in a drain (pH 6, temp. 20ºC).

Indian distribution: Savandurga, Karnataka (Gurudeva et al. 1983); Karnataka

(Bongle 1987); Gujarat (Kumar & Patel 1988); Bareilly, Uttar Pradesh (Pandey et

al. 1988); Rohilakhand, Uttar Pradesh (Habib 1993); Bihar (Kumar & Chaudhary

2009).

This is the first report of the taxon from Eastern Himalaya.

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10. Cosmarium cycladatum Turner

(Turner 1892, p. 54, pl. 8, f. 12)

[Pl. IV, f. 105, 106]

Cells medium sized, 1.4-1.5 times longer than broad; semicells semicircular;

median constriction deep, sinus closed; basal angles narrow, lateral walls convex

moderately then attenuate forming broadly rounded apex; lateral margins

granulate-crenate, crenulations broad with two minute spines at two angles each,

another two series of similar crenulations just below the margins; face of the

semicells with a bunch of elongate thickenings extending below the apex, cell

wall otherwise smooth.

Length: 49-51 µm, Breadth: 33-35 µm, Isthmus: 10-12 µm.

Present taxon differs from the type in having median thickenings, otherwise very

much similar to the typical in external morphology.

Collection No. DD-475, 09.11.2009, Khechiperi Lake, Sikkim. In association

with mucilaginous mass growing mixed with mosses beside the Lake (pH 5.5,

temp. 14°C).

Indian distribution: Eastern India (Turner 1892).

This is the first report of the taxon from Eastern Himalaya.

11. Cosmarium cyclicum Lundell var. crassum Whelden

(Prescott et al. 1981, p. 117, pl. 166, f. 7)

[Pl. III, f. 74]

Cells large, very slightly longer than broad; circular-elliptic; median constriction

very deep, the sinus very narrow with dilated exterior; semicells semi-circular,

basal angles slightly rounded; regularly crenate with about 18 crenae and with

single row of small undulations within the margin; chloroplast axial with two

pyrenoids in each semicells.

Length: 65-67 µm, Breadth: 62-64 µm, Isthmus: 23-24 µm.

Collection No. DD-90, 18.04.2009, Rimbi falls, Sikkim. In association with

brownish slimy mucilaginous mass on the rocks with wet mosses beside the falls

(pH 5, temp. 18ºC).

Indian distribution: This is probably the first report of the taxon from India.

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12. Cosmarium cymatopleurum Nordstedt

(West & GS West 1908, p. 5, pl. 65, f. 8, 9; Prescott et al. 1981, p. 118, pl. 196, f.

6, 7)

[Pl. IV, f. 102]

Cells large, 1-1.5 times longer than broad; median constriction deep, sinus closed

except the extremities; semicells trapeziform with sub-reform base, flatly undulate

lateral sides, 7 undulations per side; apex slightly produced which is truncate with

rounded angles; cell wall very finely punctate; chloroplast axial with 2 pyrenoids

per semicell.

Length: 67-68 µm, Breadth: 48-49 µm, Isthmus: 13-15 µm.

Collection No. DD-358, 13.05.09, Bulbulay, Sikkim. With phytoplankton

samples collected from shallow rock pool (pH 6, temp. 15ºC). DD-584,

12.11.2009, Namchi, Sikkim. In association with greenish scum with wet mosses

growing on soil (pH 6.5, temp. 15ºC).

Indian distribution: This is probably the first report of the taxon from India.

13. Cosmarium depressum (Nageli) Lundell var. depressum f. minutum Heimerl

(Prescott et al. 1981, p. 124, pl. 179, f. 4, 5)

[Pl. IV, f. 123]

Cells small, as broad as long, median constriction deep, sinus open with ‘V’

shaped notch; semicells elliptic, apex truncately rounded; chloroplast axial with

single pyrenoid; cell wall smooth.

Length: 20-22 µm, Breadth: 20-22 µm, Isthmus: 6-7 µm.

Collection No. DD-412, 06.11.09, Mamencho Lake, Sikkim. In association with

dark greenish filament floating freely on the surface of water (pH 6, temp. 10ºC).

Indian distribution: Eastern India (Turner 1892); Nagpur (Freitas & Kamat

1979); Gujarat (Kumar & Patel 1990a).

This is the first report of the taxon from Eastern Himalaya.

14. Cosmarium depressum (Nageli) Lundell var. reniforme West et GS West

(West & GS West 1905, p. 178, pl. 62, f. 10; Prescott et al. 1981, p. 125, pl. 179,

f. 12, 13)

[Pl. VII, f. 213, 214]

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Cells small, slightly broader than long, median constriction deep, sinus linear,

open; semicells reniform with broadly rounded apex; chloroplast axial with single

pyrenoids.

Length: 27-29 µm, Breadth: 23-25 µm, Isthmus: 6-8 µm.

Collection No. DD-585, 12.11.2009, Namchi, Sikkim. With phytoplankton

sample collected from a small waterfall (pH 6.5, temp. 15ºC).

Indian distribution: This is probably the first report of the taxon from India.

15. Cosmarium dorsitruncatum (Nordstedt) GS West var. pseudoscenedesmus (West

et GS West) Krieger et Gerloff

(Prescott et al. 1981, p. 130, pl. 181, f. 11, 12)

[Pl. VI, f. 191, 192]

Cells medium sized, 1.3-1.4 times broader than long; medium constriction deep,

sinus closed, slightly open outwardly; semicells flatly trapeziform with rounded

basal angles, apex flatly truncate; chloroplast single axial plate with a median

pyrenoid in each semicells.

Length: 25-27 µm, Breadth: 34-36 µm, Isthmus: 12-14 µm.

Collection No. DD-418, Mamencho Lake, Sikkim. In association with brownish-

yellow filamentous algal mass floating freely on the surface of the water (pH 6,

temp. 10ºC).

Indian distribution: This is probably the first report of the taxon from India.

16. Cosmarium favum West et GS West var. indicum var. nov.

[Pl. VI, f. 201, 202]

Cells large, about 1.2 times broader than long; median constriction deep, sinus

dilated at the apex, closed but inflated outwardly by the basal margins of the

semicells; semicells rectangular-reniform, lateral margins convex, apex broadly

oval; entire the cell wall ornamented with decussating rows of large granules

around each one of which is an oval and circular crease with deep punctations.

Length: 34-36 µm, Breadth: 41-44 µm, Isthmus: 15-16 µm.

External morphology of present taxon resembles C. favum West et GS West but

differs from it in,

1. Natures of the areoles (not hexagonal rather circular)

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2. Shape of the semicells (rectangular-reniform)

3. Cell broader rather longer.

Holotype No. DD-27, 16.04.2009, Pelling, Sikkim. With phytoplankton samples

collected from the water of a small Lake (pH 5, temp. 21ºC). Kept in the algae

herbarium, Department of Botany, The University of Burdwan (BURD).

17. Cosmarium galeritum Nordstedt var. subtumidum Borge

(Prescott et al. 1981, p. 144, pl. 188, f. 5, 6)

[Pl. III, f. 89; pl. IV, f. 90, 91]

Cells medium sized, 1.1-1.3 times longer than broad; median constriction deep,

the sinus closed; semicells in face view pyramidal-trapeziform, the basal and

apical angles broadly rounded; chloroplast two in each semicells with several

radiating ridges and with 2 pyrenoids; cell wall finely punctate.

Length: 49-53 µm, Breadth: 41-45 µm, Isthmus: 19-22 µm.

Collection No. DD-379, 06.11.09, Bitang-cho Lake, Sikkim. In association with

deep green filaments floating freely on the surface of water forming bloom (pH 6,

temp. 10ºC). DD-536, 10.11.2009, Sordum, Sikkim. In association with green

scum on wet rock (pH 6, temp. 15ºC).

Indian distribution: This is probably the first report of the taxon from India.

18. Cosmarium garrolense Roy et Bissett

(West & GS West 1908, p. 12, pl. 66, f. 7-8; Prescott et al. 1981, p. 144, pl. 196, f.

2; Lenzenweger 1999, p.89, pl. 53, f. 24-25)

[Pl. IV, f. 93]

Cells small, 1.2-1.3 times longer than broad, median constriction deep, sinus

linear, closed; semicells semicircular with slightly rounded basal angle; lateral

margins evenly convex with 4 undulations on each sides of semicells; apex broad

and flatly rounded; cell wall smooth.

Length: 22-24 µm, Breadth: 16-17 µm, Isthmus: 6-7 µm.

Collection No. DD-412, 06.11.09, Mamencho Lake, Sikkim. In association with

dark greenish filament floating freely on the surface of water (pH 6, temp. 10ºC).

Indian distribution: Nagpur (Freitas & Kamat 1979); Rohilakhand, Uttar

Pradesh (Habib 1993); Goalpara, Assam (Deca et al. 2011).

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19. Cosmarium garrolense Roy et Bissett var. garrolense f. dimidio-minus Gronblad

(Prescott et al. 1981, p. 144, pl. 196, f. 3)

[Pl. III, f. 87, 88]

Cells small, 1.2-1.3 times longer than broad; isthmus deep, sinus closed, linear;

semicells trapeziform with broad, slightly rounded apex; lateral margins with 4

faint undulations; cell wall smooth; chloroplast axial with single median

pyrenoids.

Length: 17-19 µm, Breadth: 13-15 µm, Isthmus: 4-6 µm.

Collection No. DD-379, 06.11.09, Bitang-cho Lake, Sikkim. In association with

light green filaments on the surface of the water (pH 6, temp. 10ºC).

Indian distribution: This is probably the first report of the taxon from India.

20. Cosmarium garrolense Roy et Bissett var. minus Kidd et Wade

(Prescott et al. 1981, p. 145, pl. 196, f. 4)

[Pl. VI, f. 164, 165]

Cells small, 1.2-1.3 times longer than broad; isthmus deep, sinus closed, linear;

semicells semicircular with retuse apex; lateral wall with 3 undulations in each

side; cell wall smooth.

Length: 21-22 µm, Breadth: 16-18 µm, Isthmus: 5-6 µm.

Collection No. DD-17, 16.04.2009, Pelling, Sikkim. In association with slimy

deep green filaments on the margin of a small water body (pH 5, temp. 19ºC).

Indian distribution: This is probably the first report of the taxon from India.

21. Cosmarium granatum Brébisson ex Ralfs var. granatum

(West & GS West 1905, p. 186, pl. 63, f. 1-3; Prescott et al. 1981, p. 145, pl. 185,

f. 1-3; Lenzenweger 1999, p. 47, pl. 50, f. 26)

[Pl. V, f. 136-138]

Cells small, 1.4-1.5 times longer than broad, median constriction deep, sinus

closed; semicells truncate-pyramidal; basal angles rounded, lateral margin

converging from the basal angles toward the narrow, truncate apex; cell wall

smooth.

Length: 28-29 µm, Breadth: 19-20 µm, Isthmus: 5-6 µm.

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In our specimen punctae is absent.

Collection No. DD-379, DD-382, 06.11.09, Bitang-cho Lake, Sikkim. In

association with deep green filaments floating freely on the surface of water

forming bloom (pH 6, temp. 10ºC). DD-435, 07.11.2009, Backthong falls, Sikkim.

In association with green filaments on the surface of the water (pH 6, temp. 14ºC).

Indian distribution: Amritsar, Punjab (Singh 1966); Bombay and Karnatak

(Bharati 1966); Gwalior, Madhya Pradesh (Agarkar 1969); Vidarbh, Maharashtra

(Kamat 1975); Uttar Pradesh (Prasad & Mehrotra 1977b); Nagpur (Freitas &

Kamat 1979); Marathwada, Maharashtra (Asthekar & Kamat 1979); Allahabad,

Uttar Pradesh (Pandey & Pandey 1980); Kashmir (Compère 1983); Karnataka

(Bongle 1987); Madhya Pradesh (Mahajan 1987); Gujarat (Kumar & Patel 1988);

Singbhum, Bihar (Das et al. 1990);Pithoragarh (Chaturvedi & Habib 1993);

Rohilkhand, Uttar Pradesh (Habib 1993); Ganga (Gupta & Shukla 1994); Nagpur,

Maharashtra (Tarar et al. 1998); Muriyad, Kerala (Sanilkumar & Thomas 2006);

Kalimpong, Tonglu, Mongpoo (Santra & Pal 2006); Uttar Pradesh (Dwivedi &

Misra 2007); Uttarakhand (Misra et al. 2008); Hartala Lake, Maharashtra (Dhande

& Jawale 2009); Uttaranchal (Shukla et al. 2008); Southern Himachal Pradesh

(Dwivedi et al. 2009).

This is a fairly common taxon of Cosmarium in India.

22. Cosmarium granatum Brébisson ex Ralfs var. elongatum Nordstedt

(West & GS West 1905, p. 189, pl. 63, f. 10; Prescott et al. 1981, p. 148, pl. 186,

f. 1, 2; Lenzenweger 1999, p. 47, pl. 50, f. 29)

[Pl. III, f. 80]

Cells medium sized, 1.6-1.7 times longer than broad, slightly elongate, isthmus

deep, sinus closed, dilated at the extremities; semicells pyramidal with rounded

basal angles, lateral margins converging to narrow, flatly rounded apex; cell wall

punctate, punctae large.

Length: 40-42 µm, Breadth: 25-26 µm, Isthmus: 6-7 µm.

Collection No. DD-389, 06.11.09, Bitang-cho Lake, Sikkim. In association with

light green filaments on the surface of the water (pH 6, temp. 10ºC).

Indian distribution: This is probably the first report of the taxon from India.

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23. Cosmarium granatum Brébisson ex Ralfs var. subangulare West et GS West

(Prescott et al. 1981, p. 149, pl. 185, f. 15, 16)

[Pl. V, f. 135]

Cells small, 1.3-1.4 times longer than broad; isthmus deep, sinus closed; semicells

semicircular with rounded basal angles; lateral walls convex strongly to narrow

retuse apex; cell wall smooth; chloroplast axial with single median pyrenoids in

each semicells.

Length: 24-25 µm, Breadth: 17-19 µm, Isthmus: 6-7 µm.

Collection No. DD-156, Kothak Lake, Sikkim. With phytoplankton samples

collected from the Lake (pH 5.5, temp. 15ºC).

Indian distribution: This is probably the first report of the taxon from India.

24. Cosmarium hammeri Reinsch var. hammeri

(West & GS West 1905, p. 181, pl. 62, f. 20, 21; Prescott et al. 1981, p. 149, pl.

182, f. 1-3; Lenzenweger 1999, p. 78, pl. 52, f. 3)

[Pl. IV, f. 124]

Cells medium sized, 1.3-1.4 times longer than broad; median constriction deep,

sinus linear, closed except the at extremities; cells in face view trapeziform, the

basal and apical angles broadly rounded, the sides slightly concave and apex

broad and truncate; wall smooth; chloroplast single in each semicells with single

pyrenoid.

Length: 27-29 µm, Breadth: 20-22 µm, Isthmus: 6-7 µm.

Collection No. DD-132, 18.04.2009, Khechiperi Lake, Sikkim. In association

with brownish mass & wooly substances lodged with the submerged leaves of

Cryptomeria plants (pH: 5.5, temp. 17°C). DD-379, 06.11.09, Bitang-cho Lake,

Sikkim. In association with deep green filaments floating freely on the surface of

water forming bloom (pH 6, temp. 10ºC).

Indian distribution: East India (Turner 1892); Kolhapur, Maharashtra (Kamat

1963); Pachmari, Madhya Pradesh (Agarkar & Agarkar 1977); Gujarat (Kumar &

Patel 1988); Sambhar and Didwana Lake, Rajasthan (Jakher et al. 1990);

Pithoragarh (Chaturvedi & Habib 1993); Nagpur, Maharashtra (Tarar et al. 1998)

Sikkim (Santra & Pal 2006); West Bengal (Debnath & Mandal 2012).

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25. Cosmarium hammeri Reinsch var. protuberans West et GS West

(West & GS West 1905, p. 183, pl. 62, f. 24, 25; Prescott et al. 1981, p. 150, pl.

182, f. 9-11)

[Pl. IV, f. 121, 122]

Cells medium sized, 1.3-1.5 times longer than broad; semicells with lateral

margins slightly convex; apex broadly concave; basal lateral angles broadly

rounded; semicells with single median tumor; chloroplast single in each semicells

with single pyrenoid.

Length: 25-39 µm, Breadth: 17-27 µm, Isthmus: 6-12 µm.

Collection No. DD-389, 06.11.09, Bitang-cho Lake, Sikkim. In association with

light green filaments on the surface of the water (pH 6, temp. 10ºC).

Indian distribution: Andhra Pradesh (Suxena & Venkateswarlu 1968a); Vidarbh,

Maharashtra (Kamat 1975); Savandurga, Karnataka (Gurudeva et al. 1983);

Bareilly, Uttar Pradesh (Pandey & Habib 1987); Goalpara, Assam (Deca et al.

2011).

26. Cosmarium hammeri Reinsch var. schmidlei Gronblad et Scott

(Prescott et al. 1981, p. 151, pl. 182, f. 12, 13)

[Pl. V, f. 139]

Cells small, 1.4-1.5 times longer than broad; median constriction deep, the sinus

closed except at the extremities; semicells in face view trapeziform, without any

median tumor, the basal and apical angles rounded; lateral walls concave; apex

flattened; cell wall smooth; chloroplast with 2 pyrenoids in each semicells.

Length: 27-28 µm, Breadth: 17-19 µm, Isthmus: 5-6 µm.

Collection No. DD-536, 10.11.2009, Sordum, Sikkim. In association with green

scum on the wet rocks (pH 6, temp. 15ºC).

Indian distribution: Andhra Pradesh (Suxena & Venkateswarlu 1966b, 1968c);

Madhya Pradesh (Agarkar et al. 1979); Allahabad, Uttar Pradesh (Pandey &

Pandey 1980a); Andaman and Nikobar Island (Prasad & Misra 1992); Pithoragarh

(Chaturvedi & Habib 1993); West Bengal (Mukherjee & Srivastava 1993); Uttar

Pradesh (Dwivedi & Misra 2007).

This is the first report of the taxon from Eastern Himalaya.

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27. Cosmarium impressulum Elfving var. impressulum

(West & GS West 1908, p. 86, pl. 77, f. 14-18; Prescott et al. 1981, p. 159, pl.

215, f. 5; Lenzenweger 1999, p. 90, pl. 53, f. 15)

[Pl. VII, f. 211, 212]

Cells small, 1.6-1.7 times longer than broad; median constriction deep, sinus

closed but dilated at the apex; semicells elongate semicircular, the basal angles

rounded, the lateral margins nearly parallel with 4 undulations, retuse at the apex;

face of the semicells smooth.

Length: 25-26 µm, Breadth: 15-16 µm, Isthmus: 4-5 µm.

Turner (1892) has proposed a forma C. impressulum f. minor which is much

smaller than the type, although Prescott et al (1981) have considered it as

synonymous with the typical as opined by Krieger & Gerloff (1965). Our

specimen is intermediate between the two.

Collection No. DD-584, 12.11.2009, Namchi, Sikkim. In association with

greenish scum with wet mosses growing on soil (pH 6.5, temp. 15ºC).

Indian distribution: Madhya Pradesh (Agarkar 1971, Dhande & Jawale 2009);

Maharashtra (Kamat 1975, Asthekar & Kamat 1979); Kashmir (Compère 1983);

Uttar Pradesh (Chaturvedi et al. 1987; Habib 1995, 2008b, 2009); Gujarat (Kumar

& Patel 1988); Kurseong, Mongpoo (Santra & Pal 2006); Hamirpur (Habib &

Chaturvedi 2007); Jayantia hills (Das et al. 2009); Kumayun Himalaya (Habib &

Chaturvedi 2011); Uttarakhand (Habib & Chaturvedi 2012).

28. Cosmarium impressulum Elfving var. suborthogonum (West et GS West) Taft f.

suborthogonum

(Taft 1945, p. 195, pl. 3, f. 9f; Prescott et al. 1981, p. 160, pl. 215, f. 2, 4;

Lenzenweger 1999, p. 51, pl. 53, f. 19, 20)

[Pl. IV, f. 98-101]

Cells small, 1.3-1.5 times longer than broad; median constriction deep, sinus

narrowly linear and closed but inflated at the apex; semicells subsemicircular, the

basal angles broadly rounded, the lateral margins in the lower of the semicell

parallel but retuse, the upper lateral margin with 2 undulations, retuse in the

midregion; face of the semicells smooth; the lateral margins protruded in the

midregion.

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Length: 26-28 µm, Breadth: 18-20 µm, Isthmus: 8-11 µm.

Collection No. DD-414, DD-418, 06.11.2009, Mamencho Lake, Sikkim. In

association with green filaments on the surface of the water (pH 6, temp. 10ºC).

Indian distribution: Gujarat (Kumar & Patel 1990a); Mamencho Lake, Sikkim

(Das & Keshri 2012).

29. Cosmarium javanicum Nordstedt

(Prescott et al. 1981, p. 165, pl. 192, f. 8)

[Pl. VI, f. 173, 174]

Cells large, about 2 times longer than broad; median constriction shallow, sinus

linear, closed but dilated at the end; lateral margins evenly convex to broadly

rounded apex; basal angles narrowly rounded; cell wall striated and punctuate,

punctae large and irregularly distributed.

Length: 121-122 µm, Breadth: 63-64 µm, Isthmus: 32-33 µm.

Collection No. DD-382, 06.11.09, Bitang-cho Lake, Sikkim. In association with

green filamentous mass attached to the surface of the submerged aquatic plants

(pH 6, temp. 10ºC).

Indian distribution: Eastern India (Turner 1892); Madhya Pradesh (Agarkar

1969; Agarkar & Agarkar 1990); Bareilly, Uttar Pradesh (Pandey & Habib 1987;

Habib & Pandey 1989); Kerala (Shaji et al. 1988); Pithoragarh (Chaturvedi &

Habib 1993); Rohilkhand, Uttar Pradesh (Habib 1993).

This is the first report of the taxon from Eastern Himalaya.

30. Cosmarium laeve Rabenhorst var. octangulare (Wille) West et GS West

(West & GS West 1908, p. 101, pl. 73, f. 20; Prescott et al. 1981, p. 169, pl. 293,

f. 17, 18; Lenzenweger 1999, p. 92, pl. 52, f. 25)

[Pl. V, f. 148]

Cells small, slightly longer than broad; isthmus deep, sinus closed, dilated at the

apex; semicells angular, irregularly 8 sided, each lateral margin consisting of 3

short, straight or very slightly concave sides; apex narrowly retuse; cell wall

punctate.

Length: 23-25 µm, Breadth: 19-21 µm, Isthmus: 5-7 µm.

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Collection No. DD-583, 12.11.2009, Namchi, Sikkim. In association with

greenish-brown scum with mosses in a small rock pool (pH 6.5, temp. 14ºC).

Indian distribution: Andhra Pradesh (Suxena & Venkateswarlu 1966b); West

Bengal (Pal & Santra 1993); Hartala Lake, Maharashtra (Dhande & Jawale 2009);

Goalpara, Assam (Deca et al. 2011).

This is the first report of the taxon from Eastern Himalaya.

31. Cosmarium levinotabile Croasdale

(Prescott et al. 1981, p. 172, pl. 198, f. 1-5)

[Pl. IV, f. 92]

Cells small, 1.3-1.5 times longer than broad with shallow, open sinus; semicells

truncate pyramidal, the basal and apical angles slightly rounded; lateral margins of

the semicell slightly concave with 3 undulations between basal and apical angles;

apex truncate and faintly bi-undulate; cell wall smooth; chloroplast axial with

single pyrenoid in each semicell.

Length: 25-26 µm, Breadth: 17-19 µm, Isthmus: 13-15 µm.

Collection No. DD-714, 01.05.2010, Kalimpong. With phytoplankton sample

collected from a roadside water body (pH 6.5, temp. 25ºC).

Indian distribution: This is probably the first report of the taxon from India.

32. Cosmarium longicylindricum Scott et Grönblad var. indicum var. nov.

[Pl. VI, f. 162, 163]

Cells large, 2-2.5 times longer than broad; median constriction shallow, the sinus

open,acute angled; semicells sub-cylindrical; lateral margins parallel; apex flatly

rounded; cell wall smooth.

Length: 51-53 µm, Breadth: 23-25 µm, Isthmus: 17-18 µm.

Present taxon is very much similar to C. longicylindricum Scott & Grönblad but

differs in,

1. Cells with smaller dimension

2. Being stouter, L/B ratio smaller

3. Isthmus shallow, acute angled.

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Holotype No. DD-585, 12.11.2009, Namchi, Sikkim. With phytoplankton sample

collected from a small waterfalls (pH 6.5, temp. 15ºC).Kept in the algae

herbarium, Department of Botany, The University of Burdwan (BURD).

33. Cosmarium lundelli Delponte var. ellipticum West et GS West

(West & GS West 1905, p. 138, pl. 57, f. 3, 4; Prescott et al. 1981, p. 179, pl.160,

f. 7)

[Pl. VII, f. 203, 204]

Cells medium sized, very slightly longer than broad; apex typically angularly

elevated; median constriction deep, the sinus linear, narrow, closed; semicells

elliptic; apex broadly rounded; cell wall closely and evenly punctate; chloroplast

with parietal lamellae with two large pyrenoids in each semicells.

Length: 44-45 µm, Breadth: 41-43 µm, Isthmus: 16-18 µm.

Present specimen is smaller than the typical.

Collection No. DD-578, 10.11.2009, Sungure, Sikkim. In association with green

filaments on the rocks under running water (pH 6, temp. 16ºC).

Indian distribution: Karnataka (Bharati 1965b); Bombay and Karnatak (Bharati

1966); Uttar Pradesh (Prasad & Mehrotra 1977a); Allahabad, Uttar Pradesh

(Pandey & Pandey 1980b); Gujarat (Kumar & Patel 1988); Pithoragarh

(Chaturvedi & Habib 1993); Uttarakhand (Misra et al. 2007); Southern Himachal

Pradesh (Dwivedi et al. 2009).

This is the first report of the taxon from Eastern Himalaya.

34. Cosmarium minimum West et GS West var. subrotundum West et GS West

(West et GS West 1895, p. 59, pl. 8, f. 11; Prescott et al. 1981, p. 189, pl. 206, f.

8)

[Pl. IV, f. 96, 97]

Cells small, 1-1.4 times longer than broad; median constriction shallow; sinus

nearly closed; semicells nearly oval; the basal angles broadly rounded; cell wall

smooth; chloroplast axial and single in each semicell, pyrenoid single.

Length: 12-17 µm, Breadth: 11-14 µm, Isthmus: 5-12 µm.

Collection No. DD-396, 06.11.09, Babamandir, Sikkim. In association with

mosses on the rock under the stream (pH 6, temp. 8ºC). DD-413, 06.11.2009,

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Mamencho Lake Sikkim. In association with light greenish-yellow filaments

attached on the surface of the wet rock (pH 6, temp. 10ºC).

Indian distribution: Mamencho Lake, Sikkim (Das & Keshri 2012).

35. Cosmarium moniliforme (Turpin) Ralfs var. moniliforme

(West & GS West 1908, p. 20, pl. 66, f. 1-3; Prescott et al. 1981, p. 191, pl.202, f.

5, 7)

[Pl. IV, f. 111]

Cells small, about twice long as broad; median constriction moderately deep, the

sinus widely open but usually acute, semicells circular, apex rounded; chloroplast

axial, one in each semicell with a central pyrenoid; cell wall finely punctate.

Length: 17-19 µm, Breadth: 10-12 µm, Isthmus: 2-3 µm.

Collection No. DD-492, 09.11.2009, Khechiperi Lake, Sikkim. From the water

squished from the bog pool (pH 6, temp. 14ºC). DD-412, 06.11.09, Mamencho

Lake, Sikkim. In association with dark greenish filament floating freely on the

surface of water (pH 6, temp. 10ºC).

Indian distribution: East India (Turner 1892); Andhra Pradesh (Suxena &

Venkateswarlu 1968a); Madhya Pradesh (Agarkar 1969; Agarkar & Agarkar 1973

1977); Bombay & Karnataka (Bharati 1966); Uttar Pradesh (Prasad & Mehrotra

1977a); Kashmir (Compère 1983); Central India (Unni 1985); Uttar Pradesh

(Pandey & Habib 1987 , Habib & Chaturvedi 1993); Gujarat (Kumar & Patel

1990a); Pithoragarh (Chaturvedi & Habib 1993); Rohilkhand, Uttar Pradesh

(Habib 1993); Nagpur, Maharashtra (Tarar et al. 1998); Uttaranchal (Khare &

Suseela 2007); Karnataka (Shekhar et al. 2008, Giriayappanavar & Patil 2010);

Jashpur, Chhattisgarh (Toppo & Suseela 2009); Kodaikanal, Tamilnadu (Singh &

Balasingh 2011); Goalpara, Assam (Deca et al. 2011); Kolhapur, Maharashtra

(Leela et al. 2012); West Bengal (Debnath & Mandal, 2012).

36. Cosmarium moniliforme (Turpin) Ralfs forma

[Pl. V, f. 147]

Cells large, 1.6 times longer than broad; median constriction shallow, the sinus

widely open, acute at the apex; semicells circular; apex broadly rounded;

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chloroplast axial with radiating small lobes, one in each semicell with a central

pyrenoid; cell wall finely punctate.

Length: 60-63 µm, Breadth: 37-38 µm, Isthmus: 29-30 µm.

Present specimen similar to the C. moniliforme (Turpin) Ralfs but differs in,

1. Larger in size

2. L/B ratio lower

3. Sinus shallow.

Such specimens are intergradiating forms, between Cosmarium & Actinotaenium.

To some extent it also looks like C. connatum (Brébisson) Ralfs.

Collection No. DD-389, 06.11.09, Bitang-cho Lake, Sikkim. In association with

light green filaments on the surface of the water (pH 6, temp. 10ºC).

37. Cosmarium montrealense Croasdale

(Prescott et al. 1981, p. 195, pl. 171, f. 13, 14)

Basionym: Cosmarium bioculatum Brébisson forma Irénéé-Marie

: Cosmarium bioculatum var. canadense Krieger et Gerloff

[Pl. V, f. 142]

Cells medium sized, slightly longer than broad; semicells transversely elliptic but

with a reniform base and strongly rounded apex; sinus closed; cell wall smooth,

circular in lateral view; chloroplast parietal with finger like projections; pyrenoid

single.

Length: 21-25 µm, Breadth: 18-22 µm, Isthmus: 5-7 µm.

Collection No. DD-412, 06.11.2009, Mamencho Lake, Sikkim. In association

with dark greenish filament floating freely on the surface of the water (pH 6,

temp. 10ºC).

Indian distribution: Mamencho Lake, Sikkim (Das & Keshri 2012).

38. Cosmarium naegelianum Brébisson

(West & GS West 1908, p. 14, pl. 66, f. 12; Prescott et al. 1981, p. 195, pl. 289, f.

3, 4)

[Pl. III, f. 85, 86]

Cells small, 1.2-1.3 times longer than broad; median constriction deep, sinus

closed, linear with slightly dilated extremities; semicells truncate-pyramidal, the

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lower angles rectangular, the lateral margins at first divergent to a prominent

protrusion and slightly convergent and 3-undulate to a truncate apex, the apical

margins slightly bi-undulate; cell wall finely punctate; in lateral view semicells

sub-hexagonal; chloroplast with single pyrenoid in each semicell.

Length: 22-23 µm, Breadth: 17-19 µm, Isthmus: 7-9 µm.

Collection No. DD-516, 10.11.2009, Dentam river, Sikkim. In association with

green filaments on the wet rocks (pH 6, temp. 19ºC).

Indian distribution: This is probably the first report of the taxon from India.

39. Cosmarium nitidulum De Notoris

(West & GS West 1905, p. 197, pl. 64, f. 1-3; Prescott et al. 1981, p. 197, pl. 189,

f. 2, 3; Lenzenweger 1999, p. 50, pl. 49, f. 5, 6)

[Pl. VI, f. 171, 172]

Cells medium sized, 1.2-1.3 times longer than broad; median constriction deep,

sinus closed except at the extremities; semicells trapeziform with rounded basal

and apical angles; lateral margins slightly convex; apex truncately rounded; cell

wall smooth; chloroplast 2 in each semicell, axial with single pyrenoids.

Length: 30-32 µm, Breadth: 23-25 µm, Isthmus: 8-10 µm.

Collection No. DD-583, 12.11.2009, Namchi, Sikkim. In association with

greenish-brown scum with mosses on a small rock pool (pH 6.5, temp. 14ºC).

Indian distribution: Banaras, Uttar Pradesh (Venkataraman 1957); Kashmir

(Compère 1983); Gujarat (Kumar & Patel 1988); Ganga (Gupta & Shukla 1994);

Nagpur, Maharashtra (Tarar et al. 1998); Uttar Pradesh (Misra & Srivastava

2003); Uttar Pradesh (Dwivedi & Misra 2007); Uttaranchal (Shukla et al. 2008);

Southern Himachal Pradesh (Dwivedi et al. 2009).

This is the first report of the taxon from Eastern Himalaya.

40. Cosmarium nudum (Turner) Gutwinski

(Prescott et al. 1981, p. 202, pl. 158, f. 2)

[Pl. VII, f. 207, 208]

Cells medium sized, as long as broad; median constriction deep, sinus 3 undulate,

slightly closed at the apex; semicells semi-circular with lateral walls having faint

undulations; basal angles produced and thickened; apex broadly rounded with

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thick wall; cell wall smooth; chloroplast axial, 2 in each semicells with single

median pyrenoids.

Length: 27-31 µm. Breadth: 27-31 µm. Isthmus: 6-10 µm.

Collection No. DD-418, 06.11.2009, Mamencho Lake, Sikkim. In association

with brownish-yellow filamentous algal mass floating freely on the surface of the

water (pH 6, temp. 10ºC).

Indian distribution: Kerala (Shaji & Patel 1990); Pithoragarh (Chaturvedi &

Habib 1993); Lakhimpur-Kheri, Uttar Pradesh (Habib 1995).

This is the first report of the taxon from Eastern Himalaya.

41. Cosmarium obsoletum (Hantzsch) Reinsch

(West & GS West 1905, p. 13, pl. 54, f. 1-3; Prescott et al. 1981, p. 203, pl. 157, f.

1, 2, 5)

[Pl. VII, f. 205, 206]

Cells medium sized, 1-1.2 times broader than long, deeply constricted; sinus

linear, closed except the extremities; semicells semicircular, depressed, apex

broadly rounded, basal angles mammillately thickened, lateral angles slightly

convex; cell wall porous; chloroplast axial, 2 in each semicells with single

pyrenoids centrally placed.

Length: 37-38 µm, Breadth: 44-45 µm, Isthmus: 14-15 µm.

Collection No. DD-417, DD-419, 06.11.2009, Mamencho Lake, Sikkim. In

association with brownish-yellow filamentous algal mass floating freely on the

surface of the water (pH 6, temp. 10ºC). DD-717, 01.05.2010, Kalimpong. With

phytoplankton sample collected from a small waterbody (pH 6.5, temp. 25ºC).

Indian distribution: Eastern India (Turner 1892); Kodaikanal, Tamilnadu

(Iyengar & Vimla Bai 1941; Bharati & Pai 1972; Singh & Balasingh 2011);

Karnataka (Bharati 1965b); Bombay and Karnatak (Bharati 1966); Madhya

Pradesh (Agarkar & Agarker 1972, Agarkar et al. 1979); Allahabad (Pandey &

Pandey 1980); Gujarat (Kumar & Patel 1988); Uttar Pradesh (Misra & Srivastava

2003; Dwivedi & Misra 2007); Western Himalaya (Shukla et al. 2008);

Uttaranchal (Shukla et al. 2008); Mani pokhar pond (Toppo & Suseela 2009);

Southern Himachal Pradesh (Dwivedi et al. 2009); Eastern Himalaya (Yasmin et

al. 2011).

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42. Cosmarium ornatum Ralfs var. sikkimicum var. nov.

[Pl. VI, f. 185, 186]

Cells large, 1.4-1.6 times longer than broad; median constriction deep, sinus

widely open and acute angled; semicels sub-ovate, tapered from a decidedly

rounded base to a rounded apex; lateral margins having a patch of prominent

rounded granules; apex with several rounded granules in two series as crown; face

of the semicells with granular protuberances which are somewhat elongated in the

midregion of the semicells; cell wall otherwise smooth.

Length: 42-43 µm, Breadth: 27-29 µm, Isthmus: 11-12 µm.

Present taxon is very much similar to the C. ornatum Ralfs var. ornatum but

differs in,

1. Sinus wide open rather closed

2. Semicels sub-ovate (rather reniform)

3. Cells somewhat longer.

No. DD-391, 06.11.09, Bitang-cho Lake, Sikkim. In association with brownish

scum attached to the surface of the submerged part of the semi aquatic plants (pH

6, temp. 10ºC). Kept in the algae herbarium, Department of Botany, The

University of Burdwan (BURD).

43. Cosmarium pakistanicum Islum

(Islam 1970, p. 926, pl. 14, f. 2)

[Pl. IV, f. 112, 113]

Cells large, about twice as long as broad; median constriction shallow; sinus

narrow, closed; semicells broadly elliptic-pyramidate in shape; basal angles

narrowly rounded, lateral margins slightly retuse in the lower half then again

slightly convex; apex broadly rounded; chloroplast having 10 longitudinal ridges;

wall punctate irregularly.

Length: 123-128 µm, Breadth: 68-70 µm, Isthmus: 49-50 µm.

Collection No. DD-379, 06.11.09, Sikkim. In association with deep green

filaments floating freely on the surface of water forming bloom (pH 6, temp.

10ºC).

Indian distribution: This is probably the first report of the taxon from India.

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44. Cosmarium phaseolus Brébisson in Ralfs var. phaseolus

(West & GS West 1905, p. 158, pl. 60, f. 12-14; Prescott et al. 1981, p. 222, pl.

171, f. 1-3; Lenzenweger 1999, p. 54, pl. 50, f. 5)

[Pl. VI, f. 176]

Cells medium sized, 1-1.3 times longer than broad; median constriction deep, the

sinus narrow, dilated at the apex; semicells reniform; apex broadly rounded; cell

wall punctate; chloroplast axial with single pyrenoid in each semicell.

Length: 34-36 µm, Breadth: 28-29 µm, Isthmus: 20-21 µm.

Collection No. DD-397, 06.11.09, Babamandir, Sikkim, In association with

mucilaginous mass on the rocks under a stream (pH 6, temp. 8ºC).

Indian distribution: Eastern India (Turner 1892); Bombay (Dixit 1937); Andhra

Pradesh (Suxena & Venkateswarlu 1968a); Uttar Pradesh (Prasad & Mehrotra

1977b); Gujarat (Kumar & Patel 1990a); Rohilkhand, Uttar Pradesh (Habib 1993);

Nagpur, Maharashtra (Tarar et al. 1998).

This is the first report of the taxon from Eastern Himalaya.

45. Cosmarium phaseolus Brébisson in Ralfs var. phaseolus f. minus Boldt

(Boldt 1887, p. 102; West & GS West 1905, p. 159, pl. 60, f. 15; Prescott et al.

1981, p. 222, pl. 171, f. 4, 5; Lenzenweger 1999, p. 55, pl. 50, f. 11)

[Pl. V, f. 143]

Cells small, more or less as long as broad or broader; median constriction deep,

sinus narrow, dilated at the apex; semicells rather narrowly reniform; wall smooth;

chloroplast axial with one pyrenoid in each semicell.

Length- 23-26 µm, Breadth- 26-28 µm, Isthmus- 3-5 µm.

Collection No. DD-412, 06.11.2009, Mamencho Lake, Sikkim. In association

with dark greenish filament floating freely on the surface of the water (pH 6,

temp. 10ºC).

Indian distribution: Bombay (Dixit 1937); Gwalior, Madhya Pradesh (Agarkar

1971); Bandhabgarh, Madhya Pradesh (Agarkar et al. 1979); Allahabad, Uttar

Pradesh (Pandey & Pandey 1980c); Hartala Lake, Maharastra (Dhande & Jawale

2009); Mamencho Lake, Sikkim (Das & Keshri 2012).

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46. Cosmarium portianum Archer

(West & GS West 1908, p. 165, pl. 88, f. 4-7; Prescott et al. 1981, p. 229, pl. 254,

f. 8, 9; Lenzenweger 1999, p. 117, pl. 60, f. 15, 16)

[Pl. VI, f. 193-195]

Cells small, 1-1.5 times longer than broad; median constriction moderately deep,

sinus broadly open with rounded extremity; semicells elliptic, granulate, granules

rounded arranged in vertical series or irregularly; chloroplast single, axial with

single pyrenoids.

Length: 20-24 µm, Breadth: 16-21 µm, Isthmus: 6-8 µm.

Collection No. DD- DD-27, 16.04.2009, Pelling, Sikkim. With phytoplankton

samples collected from a small Lake (pH 5, temp. 21ºC). DD-389, 06.11.09,

Bitang-cho Lake, Sikkim. In association with light green filaments on the surface

of the water (pH 6, temp. 10ºC).

Indian distribution: Eastern India (Turner 1892); Bombay and Karnatak (Bharati

1966); Gwalior, Madhya Pradesh (Agarkar 1971); Vidarbh, Maharashtra (Kamat

1975); Nagpur (Freitas & Kamat 1979); Kashmir (Compère 1983); Karnataka

(Bongle 1987); Andhra Pradesh (Satya Mohan 1987); Gujarat (Kumar & Patel

1988); Singbhum, Bihar (Das et al. 1990); Udalkachar, Madhya Pradesh (Habib

1991); Karnataka (Venkateshwarlu et al. 2011); Goalpara, Assam (Deca et al.

2011).

47. Cosmarium portianum Archer forma

[Pl. VI, f. 187, 188]

Cells small, relatively elongate than the typical, 1.5-1.6 times longer than broad;

median constriction deep, sinus broadly open with rounded extremity; semicells

circular, granulate, granules rounded arranged in 7 vertical series in face view;

chloroplast single, axial with single pyrenoids.

Length: 24-25 µm, Breadth: 15-16 µm, Isthmus: 4-6 µm.

Present taxon is very much similar to the C. portianum Archer but differs in,

1. Semicells circular

2. Cells longer than the typical.

Collection No. DD-27, 16.04.2009, Pelling, Sikkim. With phytoplankton samples

collected from a small Lake (pH 5, temp. 21ºC).

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48. Cosmarium portianum Archer var. nephroideum Wittrock

(West & GS West 1908, p. 167, pl. 80, f. 10, 11; Prescott et al. 1981, p. 230, pl.

254, f. 4; Lenzenweger 1999, p. 118, pl. 60, f. 17)

[Pl. IV, f. 103, 104]

Cells small, 1-1.1 times longer than broad; isthmus deep, sinus open; semicells

semicircular-elliptic; cell wall granulate granules arranged in 7 longitudinal series.

Length: 25-27 µm, Breadth: 23-25 µm, Isthmus: 9-10 µm.

Collection No. DD-379, 06.11.09, Bitang-cho Lake, Sikkim. In association with

deep green filaments floating freely on the surface of water forming bloom (pH 6,

temp. 10ºC).

Indian distribution: Vidarbh, Maharashtra (Kamat 1975); Marathwada,

Maharashtra (Asthekar & Kamat 1979); Allahabad, Uttar Pradesh (Pandey &

Pandey 1980a); Pithoragarh (Chaturvedi & Habib 1993); Nagpur, Maharashtra

(Tarar et al. 1998); Uttar Pradesh (Dwivedi & Misra 2007); Sitapur, Uttar Pradesh

(Habib 2008); Hartala Lake, Maharashtra (Dhande & Jawale 2009); Jashpur,

Chhattisgarh (Toppo & Suseela 2009); Kumayun Himalaya (Habib & Chaturvedi

2011).

This is the first report of the taxon from Eastern Himalaya.

49. Cosmarium pseudamoenum Wille

(West & GS West 1912, p. 31, pl. 102, f. 7-9; Prescott et al. 1981, p. 234, pl. 287,

f. 2-4; Lenzenweger 1999, p. 118, pl. 60, f. 22, 23)

[Pl. V, f. 133, 134]

Cells large, above twice as long as broad; median constriction only slight, sinus a

small and open notch; semicells oblong with the lateral margins very slightly

convex; apex broadly rounded; cell wall uniformly granulate, granules small,

arranged in distinct longitudinal series.

Length: 65-67 µm, Breadth: 25-26 µm, Isthmus: 22- 22 µm.

Collection No. DD-389, 06.11.09 Bitang-cho Lake, Sikkim. In association with

light green filaments on the surface of the water. DD-756, 10.11.2011, Lava, West

Bengal. In association with green filaments floats freely on the surface of a small

water body (pH 6, temp 17ºC).

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Indian distribution: Eastern India (Turner 1892); Bombay &Karnatak (Bharati

1966); Goalpara, Assam (Deca et al. 2011).

50. Cosmarium pseudocyclicum sp. nov.

[Pl. V, f. 131, 132]

Cells of medium sized, circular-elliptic in size, 1.2 times longer than broad;

median constriction deep, sinus narrow, closed; semicells semi-circular with flat

apex; lateral margins convex and crenate, 8-9 crenulations in each side, another 2

rows of small undulations just below the margins, margins of the apex with low

undulations, 5-6 in number, face of the semicells with 6 granules circularly

disposed, cell wall otherwise smooth; apical and basal angles narrowly rounded;

semicells with 2 chloroplast and 2 pyrenoids in each semicells.

Length: 52-54 µm, Breadth: 44-46 µm, Isthmus: 20-22 µm.

Present specimen is very much similar to C. cyclicum Lundell but differs in,

1. Flat apex

2. Cell less broad

3. Ring of granules in the face of the semicells.

Holotype No. DD-416, 06.11.09, Mamencho Lake, Sikkim. In association with

brownish scum attached to the surface of the submerged part of the semi aquatic

plants (pH 6, temp. 10ºC). Kept in the algae herbarium, Department of Botany,

The University of Burdwan (BURD).

51. Cosmarium pseudodebaryi sp. nov.

[Pl. IV, f. 115, 116]

Cells medium in size, about 2 times longer than broad; median constriction

shallow, sinus angularly closed, semicells sub-quadrate; lateral margins sub-

parallel forming broadly rounded apex; basal angles narrow; upper angles wide;

cell wall colourless and irregularly punctate.

Length: 71-74 µm, Breadth: 35-36 µm, Isthmus: 19-20 µm.

Present specimen is very much similar to C. debaryi Archer but differs in,

1. Cell dimension smaller

2. Sinus closed

3. Cell wall porous.

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Holotype No. DD-422, Backthong falls, Sikkim. In association with brown scum

with mosses on the wet rock surface (pH 6, temp. 14ºC). Kept in the algae

herbarium, Department of Botany, The University of Burdwan (BURD).

52. Cosmarium pseudoexiguum Raciborski

(West & GS West 1908, p. 70, f. 25, 26; Prescott et al. 1981, p. 237, pl. 208, f. 12-

14)

[Pl. III, f. 78]

Cells medium sized, 2 times longer than broad; median constriction moderate, the

sinus narrow and closed; semicells sub-quadrangular; basal angles narrowly

rounded; the lateral margins slightly retuse for half the distance to the apex and

then converging, straight to a broad, slightly rounded apex; cell wall smooth;

chloroplast axial with 2 pyrenoids in each semicell.

Length: 50-52 µm, Breadth: 25-26 µm, Isthmus: 20-22 µm.

Our specimen tallies in each respect to the type but is much larger.

Collection No. DD-194, 19.04.2009, Yoksum, Sikkim. In association with green

filaments in the swamp (pH 5.5, temp. 19ºC).

Indian distribution: Marathwada, Maharashtra (Asthekar & Kamat 1979);

Jalgaon, North Maharashtra (Mahajan & Nandan 2008).

This is the first report of the taxon from Eastern Himalaya.

53. Cosmarium pseudolundellii sp. nov.

[Pl. VI, f. 175]

Cells small, about as long as broad; median constriction deep, sinus closed except

the exterior; semicells nearly triangular; apex typically angularly elevated, broad,

basal angles rounded; cell wall smooth; chloroplast single in each semicells with a

central pyrenoid.

Length: 18-20 µm, Breadth: 18-19 µm, Isthmus: 4-5 µm.

Present specimen is much similar to C. lundellii Delponte in external morphology,

but differs,

1. Much smaller in size

2. Cell wall smooth rather punctate.

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Holotype No. DD-380, 06.11.2009 Bitang-cho Lake, Sikkim. In association with

green scum in a swamp (pH 6, temp. 10ºC). Kept in the algae herbarium,

Department of Botany, The University of Burdwan (BURD).

54. Cosmarium pseudo-obsoletum sp. nov.

[Pl. V, f. 144]

Cells large, slightly broader than long; median constriction shallow, sinus open,

‘V’ shaped; semicells semi-circular, little depressed, apex broadly convex, basal

angles mamillately thickened; cell wall perforated with vertical rows of numerous

large pores; chloroplast axial, 2 in each semicells with 2 pyrenoids.

Length: 74-77 µm, Breadth: 80-82 µm, Isthmus: 61-62 µm.

Present specimen is very much similar to C. obsoletum (Hantzsch) Reinsch but

differs in,

1. Pores in vertical rows

2. Sinus shallow, open.

Holotype No. DD-412, Mamencho Lake, Sikkim. In association with dark

greenish filaments floating freely on the surface of water (pH 6, temp. 10ºC). Kept

in the algae herbarium, Department of Botany, The University of Burdwan

(BURD).

55. Cosmarium pseudopyramidatum Lundell

(West & GS West 1905, p. 201, pl. 64, f. 9-12; Prescott et al. 1981, p. 242, pl.

193, f. 1-4; Lenzenweger 1999, p. 60, pl. 48, f. 9-12)

[Pl. VI, f. 183, 184]

Cells medium sized, 1.4-1.5 times longer than broad; median constriction

moderately deep, sinus closed, dilated at the extremities; semicells pyramidal with

lateral margins convex, basal angles rounded; apex narrowly flat with rounded

apical angles; cell wall punctate, punctae in series; chloroplast 2 in each semicell

with median pyrenoids.

Length: 49-50 µm, Breadth: 34-36 µm, Isthmus: 18-19 µm.

Collection No. DD-14, 16.04.2009, Pelling, Sikkim. In association with yellowish

green filamentous mass on damp soil in a partially shady place in the margin of a

water body (pH 5, temp. 19ºC).

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Indian distribution: Eastern India (Turner 1892); Karnataka (Bharati 1965b);

Bombay & Karnatak (Bharati 1966); Vidarbh, Maharashtra (Kamat 1975);

Allahabad, Uttar Pradesh (Pandey & Pandey 1980); Savandurga, Karnataka

(Gurudeva et al. 1983); Singbhum, Bihar (Das et al. 1990); Pithoragarh

(Chaturvedi & Habib 1993); Lakhimpur-Kheri, Uttar Pradesh (Habib 1995);

Andhra Pradesh (Sarojini 1996); Uttarakhand (Misra et al. 2008); Hartala Lake,

Maharashtra (Dhande & Jawale 2009); Goalpara, Assam (Deca et al. 2011).

56. Cosmarium pyramidatum Brébisson ex Ralfs var. indicum var. nov.

[Pl. VI, f. 166-168]

Cells large, pyramidal, about 2 times longer than broad; median constriction

shallow, sinus open ‘V’ shaped with rounded apex; lateral margins slightly

convex; attenuated forming truncate apex with rounded angles, basal angles

acutely rounded; cell wall punctate, two types of punctae, fine and slightly larger

punctae, intermingled with each other.

Length: 110-112 µm, Breadth: 57-59 µm, Isthmus: 42-44 µm.

Present specimen very much similar to C. pyramidatum Brébisson ex Ralfs in

external morphology but differs,

1. Sinus open

2. Cells longer than the original type.

Holotype No. DD-583, 12.11.2009, Namchi, Sikkim. In association with

greenish-brown scum with mosses on a small rock pool (pH 6.5, temp. 14ºC).

Kept in the algae herbarium, Department of Botany, The University of Burdwan

(BURD).

57. Cosmarium quadrum Lundell var. quadrum

(West & GS West 1912, p. 20, pl. 100, f. 3-6; Prescott et al. 1981, p. 264, pl. 283,

f. 1, 3, 5 Lenzenweger 1999, p. 120, pl. 59, f. 4, 5)

[Pl. V, f. 156, 157; pl. VI, f. 160, 161]

Cells large, slightly longer than broad; median constriction deep, the sinus

narrowly linear with a slightly dialated extremity; semicells sub-rectangular, lower

angles rounded, upper angles broadly rounded, lateral margins slightly convex,

apex very slightly retuse; cell wall densely granulate, granules solid, arranged in

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decussating, oblique series and in somewhat less distinct vertical series, 34

granules at the margin of a semicell and slightly reduced in size in the middle of

the apex.

Length: 54-68 µm, Breadth: 54-62 µm, Isthmus: 13- 20 µm.

Collection No. DD-483, 09.11.2009, Khechiperi Lake, Sikkim. From the water

squished from the bog pool (pH 6, temp. 14°C). DD-410, DD-411, 06.11.09,

Mamencho Lake, Sikkim. In association with light green filaments swims freely

on the surface of the water (pH 6, temp. 10ºC). DD-716, 01.05.2010, Kalimpong,

West Bengal. With the phytoplankton samples from a small water tank (pH 6.5

temp 25ºC).

Indian distribution: East India (Turner 1892); Ranchi, Bihar (Sinha & Mishra

1967); Andhra Pradesh (Suxena & Venkateswarlu 1968c); Madhya Pradesh

(Agarkar 1971; Agarkar & Agarkar, 1977); Vidarbh, Maharashtra (Kamat 1975);

Uttar Pradesh (Pandey & Pandey 1980; Chaturvedi et al. 1987; Habib 1993; Habib

& Chaturvedi 1993; Mishra & Ram 2007; Shukla et al. 2008); Kerala (Shaji et al.

1988); Singbhum, Bihar (Das et al. 1990); West Bengal (Pal & Santra 1993);

Nagpur, Maharashtra (Tarar et al. 1998); Siddharth Nagar (Prakash et al. 2005);

Orissa (Jena et al. 2006); Muriyad, Kerala (Sanilkumar & Thomas 2006); Sikkim,

Kalimpong (Santra & Pal 2006); North-East India (Yasmin et al. 2011); Assam

(Deka et al. 2011).

58. Cosmarium quadrum Lundell var. minus Nordstedt

(Prescott et al 1981, p. 264, pl. 283, f. 8)

[Pl. V, f. 153]

Cells small, very slightly longer than broad; median constriction deep, the sinus

narrowly linear with a slightly dilated extremity; semicells sub-rectangular, lower

angles rounded, upper angles broadly rounded, lateral margins slightly convex,

apex very slightly retuse; cell wall densely granulate, granules solid, arranged in

decussating series, 23 granules showing at the margin of the semicells and slightly

reduced in size in the middle of the apex; chloroplast axial with 2 pyrenoids in

each semicell.

Length: 39-41 µm, Breadth: 38-39 µm, Isthmus: 12-17 µm.

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150

Collection No. DD-194, 19.04.2009, Yoksum, Sikkim. In association with green

filaments in a swamp (pH 6, temp. 15ºC). DD-222, 10.05.2009, Changu Lake,

Sikkim. With phytoplankton samples collected from the Lake (pH 6, temp. 6ºC).

Indian distribution: Bombay and Karnatak (Bharati 1966); Pithoragarh

(Chaturvedi & Habib 1993); Goalpara, Assam (Deca et al. 2011).

59. Cosmarium quadratum Ralfs var. quadratum f. boreale Croasdale

(Prescott et al. 1981, p. 260, pl. 293, f. 4)

[Pl. III, f. 76]

Cells medium sized, 1.5-2 times longer than broad; median constriction moderate,

sinus closed, opening little wide toward exrterior; semicells sub-quadrate, lower

angles narrowly rounded, lateral angles slightly retuse and ver slightly tapered to a

flatly rounded apex; cell wall finely punctate; chloroplast axile, covering almost

entire region of the semicells, pyrenoids 2 in each semicell.

Length: 57-58 µm, Breadth: 32-33 µm, Isthmus: 21-22 µm.

Collection No. DD-289, 12.05.2009, Backthong falls, Sikkim. In association with

phytoplankton with mosses on the rocks beside the falls (pH 6, temp. 15ºC). DD-

728, 02.05.2010, Mach pokhri, West Bengal. With phytoplankton sample

collected from the waterbody (pH 6.5, temp. 22ºC).

Indian distribution: This is probably the first report of the taxon from India.

60. Cosmarium quadratum Ralfs var. quadratum f. willei

(West & GS West 1908, p. 59, pl. 87, f. 21, 22; Prescott et al. 1981, p. 261, pl.

293, f. 6, 7; Lenzenweger 1999, p. 84, pl. 51, f. 35a)

[Pl. III, f. 77]

Cells medium sized, 1.4-1.5 times longer than broad; median constriction

moderate, the sinus narrow, opening rather widely toward the exterior; semicells

sub-quadrate, lower angles narrowly rounded and slightly protruding, the lateral

margins slightly convex, becoming little broader toward the broadly rounded

apex; cell wall smooth; chloroplast axial converging the entire part of the semicell

with 2 pyrenoids.

Length: 57-58 µm, Breadth: 38-39 µm, Isthmus: 21-22 µm.

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Collection No. DD-289, 12.05.2009, Backthong falls, Sikkim. In association with

phytoplankton with mosses on the rocks beside the falls (pH 6, temp. 15ºC).

Indian distribution: Vidarbh, Maharashtra (Kamat 1975).

This is the first report of the taxon from Eastern Himalaya.

61. Cosmarium regnesi Reinsch

(West & GS West 1908, p. 36, pl. 68, f. 19-28; Prescott et al. 1981, p. 274, pl.

263, f. 2-4; Lenzenweger 1999, p. 126, pl. 61, f. 7)

[Pl. VII, f. 217, 218]

Cells small, as long as broad; median constriction deep, sinus widely open,

rounded; semicells transversely oblong rectangular with apex widely retuse;

margin of the semicell with 6 minute teeth, 2 apical and 2 lateral; another pair of

same teeth on the face of the semicells.

Length: 11-12 µm, Breadth: 11-12 µm, Isthmus: 5-6 µm.

Collection No. DD-380, 06.11.2009 Bitang-cho Lake, Sikkim. In association with

green scum in a swamp (pH 6, temp. 10ºC).

Indian distribution: Simla, Himachal Pradesh (Kamat 1968b); Gwalior, Madhya

Pradesh (Agarkar 1971); Uttar Pradesh (Prasad & Mehrotra 1977b); Karnataka

(Hegde 1986b).

This is the first report of the taxon from Eastern Himalaya.

62. Cosmarium reniforme (Ralfs) Archer var. minor Irénée-Marie

(Prescott et al. 1981, p. 277, pl. 259, f. 8,)

[Pl. V, f. 154, 155]

Cell medium sized, 1.1-1.3 times longer than broad; median constriction deep, the

sinus narrow and closed; semicells reniform; cell wall granulate, granules

rounded, solid, disposed in obliquely decussating series, about 16 granules

showing at the margins of the semicells.

Length: 21-23 µm, Breadth: 19-23 µm, Isthmus: 4-6 µm.

Our specimen is much smaller but very much similar in morphology.

Prescott et al (1981) doubts the validity of this variety as it differs from the typical

in mere dimension which in case of Irénée-Marie (1956) not much differ. Prescott

et al (1981) still retained this variety since it is a smaller variety. Our specimen is

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still smaller and it appears that such forms are not uncommon. Although our

specimen as much smaller, we have retained this under the variety ‘minor’

subscribing to the validity of the form described.

Collection No. DD-583, 12.11.2009, Namchi, Sikkim. In association with

greenish-brown scum with mosses on a small rock pool (pH 6.5, temp. 14ºC).

Indian distribution: This is probably the first report of the taxon from India.

63. Cosmarium retusiforme (Wille) Gutwinski

(West & GS West 1905, p. 180, pl. 57, f. 17-18; Prescott et al. 1981, p. 279, pl.

219, f. 5; Lenzenweger 1999, p. 84, pl. 52, f. 8)

[Pl. VII, f. 215, 216]

Cells small, 1.3-1.4 times longer than broad; median constriction deep, sinus

narrow, semicells sub-pyramidal with truncate apex; basal angles broadly

rounded, lower part of the lateral margin slightly convex, the upper portion

retusely converging to the poles; cell wall smooth; chloroplast axial, single in each

semicell with a pyrenoid.

Length: 21-22 µm, Breadth: 15-16 µm, Isthmus: 6-7 µm.

Collection No. DD-27, 16.04.2009, Pelling, Sikkim. With phytoplankton samples

collected from the water of a small Lake (pH 5, temp. 21ºC).

Indian distribution: Eastern India (Turner 1892); Bombay and Karnatak (Bharati

1966); Kashmir (Suxena & Venkateswarlu 1968b); Vidarbh, Maharashtra (Kamat

1975); Uttar Pradesh (Prasad & Mehrotra 1977b); Allahabad, Uttar Pradesh

(Pandey & Pandey 1980); Gujarat (Kumar & Patel 1988); Uttar Pradesh (Misra &

Srivastava 2003); Uttar Pradesh (Dwivedi & Misra 2007); Jayantia hills (Das et al.

2009); Karnataka (Venkateshwarlu et al. 2011).

64. Cosmarium rosae Růžička

(Prescott et al. 1981, p. 280, pl. 260, f. 3, 4)

[Pl. V, f. 140, 141]

Cells medium sized, slightly longer than broad; median constriction deep, sinus

closed, linear; semicells elliptic-reniform; lateral margins with faint undulations, 5

undulations in each side; apex broad, rounded, smooth; cell wall punctate;

chloroplast axial, single in each semicells with single pyrenoids.

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Length: 29-32 µm. Breadth: 25-29 µm. Isthmus: 12-15 µm.

Collection No. DD-410, 06.11.09, Mamencho Lake, Sikkim. In association with

deep green filaments floating freely on the surface of water forming bloom (pH 6,

temp. 10ºC).

Indian distribution: This is probably the first report of the taxon from India.

65. Cosmarium sikkimicum sp. nov.

[Pl. VI, f. 199, 200]

Cells large, slightly broader than long; median constriction shallow, sinus wide

open with acute end; semicells depressed semi-circular, apex broadly convex,

basal angles mamillately thickened, narrowly rounded; entire cell wall covered by

wooly hairs; chloroplast with 2 pyrenoids.

Length: 59-60 µm. Breadth: 63-64 µm. Isthmus: 40-41 µm.

It looks like C. taxichondrum Lundell & C. obsoletum (Hantzsch) Reinsch in

general morphology but differs in,

1. Larger size

2. Broader isthmus region

3. Sinus wide open

4. Covering by wooly hairs.

Holotype No. DD-380, 06.11.2009, Bitang-cho Lake, Sikkim. In association with

green scum in a swamp (pH 6, temp. 10ºC). Kept in the algae herbarium,

Department of Botany, The University of Burdwan (BURD).

66. Cosmarium sinostegos Schaarschmidt

(West & GS West 1908, p. 79, pl. 71, f. 39; Prescott et al. 1981, p. 286, pl. 220, f.

11, 12, 14)

[Pl. V, f. 159]

Cells small, about as broad as long; median constriction deep, sinus narrow;

semicells transversely elliptic, the lateral angles knob-like, converging to the

retuse apex, upper angles rounded; cell wall smooth.

Length: 8-10 µm. Breadth: 7-8 µm. Isthmus: 1-2 µm.

Our taxa differs from the original description in

1. Apex retuse

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2. Cells less broad

otherwise, very similar to the typical.

Collection No. DD-488, 09.11.2009, Khechiperi Lake, Sikkim. In association

with blackish mass with weeds (Potamogeton sp.) lodged on roots (pH 6, temp.

14ºC).

Indian distribution: Bombay and Karnatak (Bharati 1966).

This is the first report of the taxon from Eastern Himalaya.

67. Cosmarium subcrenatum Hantzsch

(Prescott et al. 1981, p. 299, pl. 239, f. 7; Lenzenweger 1999, p. 150, pl. 63, f. 22)

[Pl. V, f. 158]

Cells small, slightly broader than long; median constriction deep; sinus narrow

and closed; semicells semi-circular with truncate apex; lateral margins convex and

converging to the apex having 6 low crenations, basal angles narrowly rounded;

face of the semicells with 3 concentric rows of small granules arranged at the

periphery leaving the median portion of the semicells smooth; chloroplast single

in each semcells with a central pyrenoid.

Length: 27-29 µm, Breadth: 28-30 µm, Isthmus: 10-11 µm.

Collection No. DD-379, 06.11.09, Bitang-cho Lake, Sikkim. In association with

deep green filaments floating freely on the surface of water forming bloom (pH 6,

temp. 10ºC).

Indian distribution: Eastern India (Turner 1892); Nagpur (Freitas & Kamat

1979); Allahabad, Uttar Pradesh (Pandey & Pandey 1980); Pithoragarh

(Chaturvedi & Habib 1993); Nagpur, Maharashtra (Tarar et al. 1998); Kalimpong

(Santra & Pal 2006); Jashpur, Chhattisgarh (Toppo & Suseela 2009); Goalpara,

Assam (Deca et al. 2011).

68. Cosmarium subcucumis Schmidle var. subcucumis

(West & GS West 1905, p. 155, pl. 60, f. 1-3; Prescott et al. 1981, p. 301, pl. 169,

f. 4-6; Lenzenweger 1999, p. 67, pl. 47, f. 14, 15)

[Pl. V, f. 149-152]

Cells medium sized, 1.5-2 times longer than broad; median constriction deep, the

sinus linear, usually dilated toward the extremity; semicells semi-elliptic with

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convex sides and rounded apex; chloroplast 2, axial, each with large pyrenoid; cell

wall smooth.

Length: 49-60 µm. Breadth: 29-33 µm. Isthmus: 13-23 µm.

Collection No. DD-415, 06.11.09, Mamencho Lake, Sikkim. In association with

green filaments attached on the surface of the partially submerged rocks (pH 6,

temp. 10ºC). DD- 387, 06.11.09, Bitang-cho Lake, Sikkim. Light green filaments

floating freely on the surface of the water (pH 6, temp. 10ºC).

Indian distribution: Maharashtra (Kamat 1963; Tarar et al. 1998); Kashmir

(Suxena & Venkateswarlu 1968b); Singbhum, Bihar (Das et al. 1990); Dhunti,

Ranchi (Das and Purti 1990); Southern Himachal Pradesh (Dwivedi et al. 2009).

This is the first report of the taxon from Eastern Himalaya.

69. Cosmarium subphaseolanum sp. nov.

[Pl. VI, f. 179, 180]

Cells small, slightly longer than broad; median constriction deep, sinus narrow,

angular, dilated at the extremities; semicells narrowly reniform; basal angles

narrowly rounded, apex broadly rounded, flat in the midregion, face of the

semicells with a pair of small protuberance in the midregion on either side; cell

wall finely punctate, punctae minute; chloroplast axial with single pyrenoid.

Length: 18-19 µm, Breadth: 16-18 µm, Isthmus: 4-5 µm.

Present specimen very much similar to C. phaseolus Brébisson ex Ralfs but

differs,

1. Smaller in every respect

2. Face of the semicells with 2 protuberances instead of one.

Holotype No. DD-380, 06.11.2009, Bitang-cho Lake, Sikkim. In association with

green scum in a swamp (pH 6, temp. 10ºC). Kept in the algae herbarium,

Department of Botany, The University of Burdwan (BURD).

70. Cosmarium subquadratum Nordstedt

(West & GS West 1908, p. 57, pl. 70, f. 5; Prescott et al. 1981, p. 311, pl. 210, f.

4; Lenzenweger 1999, p. 67, pl. 51, f. 24)

[Pl. III, f. 75]

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Cells large, 2-2.5 times longer than broad; median constriction shallow, sinus

angularly open, wider at the exterior; semicells quadrate-pentahedral, the basal

angles narrowly rounded, the lateral margins parallel at first and then converging

to a flat apex; cell wall finely punctate; chloroplast axial with 2 pyrenoids in each

semicell.

Length: 81-83 µm, Breadth: 36-38 µm, Isthmus: 22-24 µm.

Collection No. DD-289, 12.05.2009, Backthong falls, Sikkim. In association with

phytoplankton with mosses on the rocks beside the falls (pH 6, temp. 15ºC).

Indian distribution: Eastern India (Turner 1892); Kerala (Sekar et al. 2004).

This is the first report of the taxon from Eastern Himalaya.

71. Cosmarium subtumidum Nordstedt

(West & GS West 1905, p. 192, pl. 63, f. 18-20; Prescott et al. 1981, p. 315, pl.

187, f. 4-7; Lenzenweger 1999, p. 68, pl. 49, f. 19)

[Pl. VI, f. 177, 178]

Cells medium sized, slightly longer than broad; median constriction deep, sinus

closed but open outwardly; semicells pyramidal with lateral margins broadly

convex, basal angles rounded, apical angles broad; apex broadly rounded; cell

wall irregularly and finely punctate.

Length: 21-22 µm, Breadth: 18-19 µm, Isthmus: 6-7 µm.

Collection No. DD-17, 16.04.2009, Pelling, Sikkim. In association with deep

green slimy filamentous mass in the margin fo a small water body (pH 6, temp.

19ºC).

Indian distribution: Eastern India (Turner 1892); Amritsar, Punjab (Singh 1966);

Kashmir (Suxena & Venkateswarlu 1968b); Vidarbh, Maharashtra (Kamat 1975);

Uttar Pradesh (Prasad & Mehrotra 1977); Nagpur (Freitas & Kamat 1979);

Allahabad, Uttar Pradesh (Pandey & Pandey 1980); Kashmir (Compère 1983);

Andhra Pradesh (Satya Mohan 1987); Singbhum, Bihar (Das et al. 1990);

Pithoragarh (Chaturvedi & Habib 1993); Jalgaon, North Maharashtra (Mahajan &

Nandan 2008); Goalpara, Assam (Deca et al. 2011).

72. Cosmarium tithophorum Nordstedt

(Prescott et al. 1981, p. 329, pl. 175, f. 13, 14)

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[Pl. VI, f. 196, 197]

Cells medium sized, slightly longer than broad; median constriction deep, sinus

widely open from a narrow apex; semicells transversely elliptic with basal angles

narrowly rounded, apex strongly rounded; face of the semicells with a mamilli in

the middle, cell wall otherwise smooth; chloroplast axial, single in each semicell.

Length: 21-22 µm, Breadth: 19-21 µm, Isthmus: 4-5 µm.

Collection No. DD-584, 12.11.2009, Namchi, Sikkim. In association with

greenish scum with wet mosses growing on soil (pH 6.5, temp. 15ºC).

Indian distribution: Eastern India (Turner 1892).

This is the first report of the taxon from Eastern Himalaya.

73. Cosmarium transitorium (Heimerl) Ducellier

(Prescott et al. 1981, p. 331, pl. 163, f. 1-3; Lenzenweger 1999, p. 71, pl. 47, f. 19)

[Pl. V, f. 146]

Cells medium sized, 1.3-1.4 times longer than broad; median constriction deep,

the sinus closed but wider in the outer part; semicells broadly elliptic; basal angles

narrowly rounded, apex conically rounded; cell wall with fine, dense punctae;

chloroplast axial with 2 pyrenoids in each semicell.

Length: 67-68 µm, Breadth: 49-51 µm, Isthmus: 25-26 µm.

Collection No. DD-194, 19.04.2009, Yoksum, Sikkim. In association with green

filament in a swamp (pH 5 temp. 19ºC). DD-284, 11.05.2009, Backthong falls,

Sikkim. In association with blackish mass of liverworts on the wet rock (pH 6,

temp. 15ºC).

Indian distribution: This is probably the first report of the taxon from India.

74. Cosmarium trilobulatum Reinsch

(West & GS West 1905, p. 185, pl. 57, f. 28-30; Prescott et al. 1981, p. 331, pl.

183, f. 11-13; pl. 221, f. 8; Lenzenweger 1999, p. 86, pl. 52, f. 5)

[Pl. VI, f. 198]

Cell small, slightly longer than broad; median constriction deep, sinus closed,

linear; semicells with 3 lobes, basal lobes very slightly rounded, upper portion of

lateral margins retuse, apex flat, apical angles acute; cell wall irregularly and

finely punctate; chloroplast single with single pyrenoid in each semicells.

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Length: 18-19 µm, Breadth: 16-18 µm, Isthmus: 6-7 µm.

Collection No. DD-583, 12.11.2009, Namchi, Sikkim. In association with

greenish-brown scum with mosses on a small rock pool (pH 6.5, temp. 14ºC).

Indian distribution: Gwalior, Madhya Pradesh (Agarkar 1969); Bombay &

Karnatak (Bharati 1966); Allahabad (Pandey & Pandey 1980); Kerala (Shaji et al.

1988); Gujarat (Kumar & Patel 1988); Hartala Lake, Maharashtra (Dhande &

Jawale 2009); Eastern Himalaya (Yasmin et al. 2011).

75. Cosmarium tyrolicum (Nordstedt) Krieger et Gerloff

(Prescott et al. 1981, p. 339, pl. 165, f. 6 & pl. 116, f. 1; Lenzenweger 1999, p.

100, pl. 54, f. 1)

[Pl. IV, f. 114]

Cells large, about 1.2 times longer than broad, median constriction deep, the sinus

closed at the extremity then wider outwardly forming a V-shaped notch; semicells

semi-elliptic, basal angles rounded, apex truncate, lateral margins slightly convex

having 6 faint undulations in each side; cell wall punctate; chloroplast axile with 2

pyrenoids in each semicells.

Length: 70-71 µm, Breadth: 57-59 µm, Isthmus: 12-13 µm.

Collection No. DD-289, 12.05.2009, Backthong falls, Sikkim. In association with

mosses as phytoplankton on the wet rock (pH 6, temp. 15ºC).

Indian distribution: This is probably the first report of the taxon from India.

76. Cosmarium undulatum Corda ex Ralfs var. alaskanum Croasdale f. reductum

Croasdale

(Prescott et al. 1981, p. 340, pl. 167, f. 11)

[Pl. IV, f. 117-120]

Cell medium sized, 1.3-1.6 times longer than broad; median constriction deep,

sinus closed (sometimes open), linear; semicells pyramidal with convex lateral

walls; entire margins with apex undulate regularly, 8 undulations per semicell; cell

wall smooth.

Length: 24-38 µm, Breadth: 18-23 µm, Isthmus: 6-14 µm.

One specimen is bit smaller and another have sinus open than the typical but very

much similar in morphology.

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Collection No. DD-379, 06.11.09, Bitang-cho Lake, Sikkim. In association with

deep green filaments floating freely on the surface of water forming bloom (pH 6,

temp. 10ºC). DD-414, 06.11.09, Mamencho Lake, Sikkim. In association with

green filamentous mass attached to the surface of the submerged aquatic plants

(pH 6, temp. 10ºC).

Indian distribution: This is probably the first report of the taxon from India.

77. Cosmarium undulatum Corda ex Ralfs var. indicum var. nov.

[Pl. VI, f. 169, 170]

Cells of medium sized, 1.1-1.3 times longer than broad; median constriction deep,

sinus closed, dilated at the extremities; semicells semi-circular, slightly elongate;

lateral margins convex forming broadly rounded apex with 15-17 smooth, equal

undulations; basal angles acute; another 2 series of concentric undulations just

below the margin, face of the semicells with 4 concentric granules arranged semi-

circularly; semicells with single axial chloroplast with a median pyrenoid.

Length: 28-31 µm, Breadth: 23-26 µm, Isthmus: 14-15 µm.

Present specimen is similar in external morphology to C. undulatum Corda ex

Ralfs var. wollei West but differs in,

1. 4 granules at the face of the semicells in a ring

2. 2 rows of undulations just below the margin

3. Cell dimension small than the type.

Holotype No. DD-417, 06.11.09, Mamencho Lake, Sikkim. In association with

greenish-brown scum on the surface of the wet rock (pH 6, temp. 10ºC). Kept in

the algae herbarium, Department of Botany, The University of Burdwan (BURD).

78. Cosmarium undulatum Corda ex Ralfs var. minutum Wittrock

(Prescott et al. 1981, p. 341, pl. 167, f. 7-9)

[Pl. VII, f. 209, 210]

Cells small, 1.2-1.3 times longer than broad; median constriction deep, sinus

closed linear; semicells sub-semicircular with lateral margins convex, apex flat,

apical angles rounded; entire margins including apex with faint undulations, 9

undulations in each semicells, cell wall smooth; chloroplast axial, single with a

median pyrenoids in each semicells.

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Length: 16-36 µm, Breadth: 13-29 µm, Isthmus: 5-22 µm.

One specimen is smaller and other has a shallow isthmus than the typical,

otherwise very much similar in morphology with the typical.

Collection No. DD-380, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with green scum in a swamp (pH 6, temp. 10ºC). DD-414, 06.11.09, Mamencho

Lake, Sikkim. In association with green filamentous mass attached to the surface

of the submerged aquatic plants (pH 6, temp. 10ºC). DD-396, 06.11.09,

Babamandir, Sikkim. In association with mosses on the rock under the stream (pH

6, temp. 8ºC). DD-714, 01.05.2010, Kalimpong. With phytoplankton sample

collected from a roadside water body (pH 6.5, temp. 25ºC).

Indian distribution: Simla, Himachal Pradesh (Kamat 1968b); Kashmir (Suxena

& Venkateswarlu 1968b); Maharashtra (Kamat 1963, 1974, 1975); Uttar Pradesh

(Prasad & Mehrotra 1977); Nagpur (Freitas & Kamat 1979); Nagpur, Maharashtra

(Tarar et al. 1998).

This is the first report of the taxon from Eastern Himalaya.

79. Cosmarium undulatum Corda ex Ralfs var. wollei West

(West & GS West 1905, p. 150, pl. 59, f. 8-10; Prescott et al. 1981, p. 341, pl.

168, f. 13-15; Lenzenweger 1999, p. 102, pl. 53, f. 30)

[Pl. IV, f. 94, 95]

Cells medium sized, slightly longer than broad; median constriction deep, sinus

closed, narrowly linear with dilated extremities; semicells semi-circular with flat

apex; lateral walls convex, apical and basal angles rounded; margins of the

semicells faintly undulate; 21 undulations per semicells; cell wall smooth,

chloroplast axial, single with a median pyrenoids in each semicell.

Length: 31-37 µm, Breadth: 28-31 µm, Isthmus: 14-15 µm.

Collection No. DD-410, 06.11.09, Mamencho Lake, Sikkim. In association with

green filaments on the surface of the water (pH 6, temp. 10ºC).

Indian distribution: Vidarbh, Maharashtra (Kamat 1975); Nagpur, Maharashtra

(Tarar et al. 1998).

This is the first report of the taxon from Eastern Himalaya.

80. Cosmarium vittanum Turner

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(Turner 1892, p. 53, pl. 8, f. 9)

[Pl. III, f. 81]

Cells medium sized, slightly longer than broad, median constriction deep, sinus

closed, dilated at the apex; broadly rounded, basal angles narrow, apex flatly-

rounded; margins undulate; face of the semicells with concentric series of small

smooth granules; chloroplast axial with a central pyrenoids.

Length: 27-29 µm, Breadth: 23-25 µm, Isthmus: 7-8 µm.

Collection No. DD-216, 10.05.2009, Changu Lake, Sikkim. In association with

mosses as phytoplankton lodged in a rock pool beside the Lake (pH 6, temp. 6ºC).

Indian distribution: Eastern India (Turner 1892); Eastern Himalaya (Yasmin et

al. 2011).

81. Cosmarium yoksomum sp. nov.

[Pl. III, f. 79]

Cells large, 1.5 times longer than broad, median constriction deep, sinus narrow,

closed, dilated at the extremities; semicells semi-circular, lateral margins convex,

basal angles acute, apex broadly rounded; lateral wall closely teethed with low,

cone-shaped tooth, 20 in number, face of the semicells densely undulate with

definite vertical rows; chloroplast 2 in each semicells with a pyrenoid.

Length: 61-63 µm, Breadth: 41-42 µm, Isthmus: 14-15 µm.

Present specimen similar to C. brebissonii Meneghini ex Ralfs in morphology but

differs in,

1. Isthmus deep, dilate

2. Tooth smaller, blunt

3. Cell stouter

4. Basal angles acute

5. Semicells semicircular.

Holotype No. DD-191, 19.04.2009, Yoksum, Sikkim. In association with

phytoplankton sample under a rock pool beside a small falls (pH 5, temp. 18ºC).

Kept in the algae herbarium, Department of Botany, The University of Burdwan

(BURD).

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V. Desmidium Agardh ex Ralfs

Cells of variable shape usually transversely narrowly oblong, oblong-semielliptical,

pyramidal-truncate or barrel-shaped usually broader than long, rarely as long as

broad, with a distinct moderately deep median constriction, sometimes completely

lacking; semicells in vertical view elliptic, with mamillate poles or 3-5 angled. Cells

united loosely to form twisted filaments, filaments sometimes embedded in a broad,

thick mucilaginous covering. Taxa those with elliptic vertical view attached to each

other usually by the close apposition of ridge-like thickening on adjacent apices and

in case of angular forms by short processes projecting from the apices of the cell, one

at each corner. Chloroplast axial, lobbed, single in each semicell with a single

pyrenoid in each chloroplast, chloroplast radiating from the center into each angle.

Cells always smooth-walled.

Key to the taxa investigated:

1. Cells triangular, with prominent isthmus……...…(1) D. aptogonum var. aptogonum

1. Cells tetrangular, with very faint isthmus

2. Cells longer than broad, isthmus region with no prominent undulation

………...…(3) D. baileyi var.tetragonum

2. Cells generally broader than long, isthmus region with faint undulations

` …………...…....(2) D. baileyi var. minus

1. Desmidium aptogonum Brébisson ex Archer var. aptogonum

(West et al. 1923, p. 242, pl. 164, f. 1-3; Croasdale et al. 1983, p. 39, pl. 463, f. 7,

8)

[Pl. XXVII, f. 446, 447]

Cells of medium sized, triangular, about 1.5 times longer than broad, median

constriction moderate, sinus open; semicells transversely oblong, with a small

basal swelling around isthmus, then narrowed to the apex which is broad and

concave in the midregion; apex produced at the angles to form connecting

processes.

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Length: 15-20 µm, Breadth: 26-29 µm, Isthmus: 22-23 µm.

Collection No. DD-141, 18.04.2009, Khechiperi Lake, Sikkim. In association

with wet mosses on the banks of the Lake (pH 4, temp 17ºC).

Indian distribution: Kashmir (Compère 1983); Goalpara, Assam (Deca et al.

2011).

2. Desmidium baileyi (Ralfs) Nordstedt var. baileyi f. minus (Allorge et Allorge)

Bicudo

(Croasdale et al. 1983, p. 41, pl. 464, f. 10)

[Pl. XXVII, f. 448, 449]

Cells of medium size, slightly broader than long, faintly constricted, sinus reduced

to faint undulations; semicells rectangular, the lateral margins parallel; the apices

with a broad, deep semielliptic depression in the middle but produced at the angles

to form fairly long connecting processes so that a cavity of considerable size is left

between the adjacent cells; semicells in vertical view 4-angled.

Length: 14-15 µm, Breadth: 20-22 µm, Isthmus: 19-20 µm.

In gross morphology the present specimen resembles D. baileyi (Ralfs) Nordstedt

f. minus (Allorge et Allorge) Bicudo but differs in,

1. Larger dimension

2. Rectangular semicells with four tetra-radiate processes.

Collection No. DD-388, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with dark green filaments on the surface of the water (pH 6, temp 10ºC).

Indian distribution: This is probably the first report of the taxon from India.

3. Desmidium baileyi Nordstedt var. tetragonum Nordstedt

(Ling & Tyler 1986, p. 25, pl. 9, f. 11-13)

[Pl. XXVII, f. 450, 451]

Cells of medium size, about as long as broad; faintly constricted, sinus reduced to a

faint undulation; semicells rectangular, lateral margin parallel, the apices with a

broad, deep semi-elliptic depression in the middle, but produced at the angles to

form fairly long connecting processes which are 4 in number attached end to end

forming a cavity of considerable size left between the adjacent cells; chloroplast

axial, four radiate.

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Length: 21-28 µm, Breadth: 22-23 µm.

Collection No. DD-387, 09.11.2009, Mamencho Lake, Sikkim. In association with

green filaments on the surface of the water (pH 6, temp 10ºC). DD-715,

01.05.2010, Kalimpong, West Bengal. In association with wet mosses growing on

the bark of tree.

Indian distribution: Gwalior, Madhya Pradesh (Agarkar 1971); Uttar Pradesh

(Pandey & Pandey 1980); Karnataka (Bongle 1987); Sikkim (Santra & Pal 2006).

VI. Euastrum Ehrenberg ex Ralfs

Cells solitary, usually short, oval in outline with deep median constriction in the

middle and also a shallow or deep vertical notch in the apex in the apex, sometimes it

may be slightly retuse or straight. Semicells may be elliptical, oval or quadrate in

outline and are mostly with 3 distinct lobes, 2 basal lobes and a polar lobe. Sometimes

there are upper lateral lobules between polar and basal lobes. Cell wall smooth,

punctate, scrobiculate or variously ornamented with granules, verrucae or short spines

either on the face or on the margins of the lobes, Chloroplast single, axial with one or

several pyrenoids in each semicells.

Key to the taxa investigated:

1. Apical margins of the polar lobes with narrow, vertical incision

2. Apical angles of the cells with prominent spines or granules

3. Apical angles with small granules.............................(14) E. pseudocoralloides

3. Apical angles with prominent spines

4. Face of the semicells with circle of granules

5. Apex convex, undulate, face of the semicells with 5-6 big granules

circularly arranged with a median mucilage pore

………...(4) E. bidentatum var. oculatum

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5. Apex flat, face of the semicells with a median small circle of relatively

small granules

6. Apex flat, face of the semicells with a single median small circle of 3

granules……………………….................(18) E. turnerii var. turnerii

6. Apex slightly elevated, face of the semicells with 2 circles of 4

granules each…………………...............(5) E. ciastonii var. ciastonii

4. Face of the semicells smooth, sometimes slightly elevated

7. Face of the semicells with 4 small granules, polar lobes produced

…...(7) E. denticulatum var. quadriferum

7. Face of the semicells smooth, slightly elevated median portion, polar

lobes less produced......(6) E. denticulatum var. denticulatum f. glabrum

2. Apical angles of the cells smooth

8. Cells dimension large, length more than 100 µm long

9. Face of the semicells with median basal protuberance downwardly directed

….................................(9) E. humerosum

9. Face of the semicells without any median ornamentation..(12) E. oblongum

8. Cell dimension relatively small, length less than 100 µm

10. Lateral margins with single, low protrusions

11. One small undulation present just below the basal, lateral and apical

angles, lateral margins retuse greatly, cell wall smooth

…..…(1) E. ampullaceum var. incavatum

11. No such ornamentation present on the face of the semicells, lateral

margins retuse slightly, cell wall coarsely punctate

...............(3) E. ansatum var. dideltiforme

10. Lateral margins without any protrusions

12. Face of the semicells with 3 basal protrusions, cell wall punctate

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….................(2) E. ansatum var. ansatum

12. Face of the semicells with slight median swelling, cell wall smooth

…..........(11) E. obesum var. subangulare

1. Apical margins of the polar lobes only retuse slightly or flat but without having any

incision

13. Lateral margins without any lateral lobes, only retuse

14. Basal lobes narrowly rounded, not produced

....(10) E. lütkemülleri var. lütkemülleri

14. Basal lobes much produced, horizontally directed, broadly rounded

15. Face of the semicells with one circle of granules at the midregion

16. Apex retuse, sinus narrowly ‘V’-shaped

….....(13) E. platycerum var. eximium f. clausum

16. Apex flat, 3 undulate, sinus ‘U’-shaped................(8) E. diplostauron

15. Face of the semicells with 3 circles of granules, one at the midregion

and one smaller circle on each of the basal lobes

……………....(17) E. subhypochondrum

13. Lateral margins with single lateral lobes, upwardly directed

17. Cells nearly circular in outline, slightly longer than broad, basal angles

broadly rounded......................................(15) E. spinulosum var. spinulosum

17. Cells nearly undulate in outline, slightly broader than long, angles narrowly

rounded………………………………............(16) E. spinulosum var. lindae

1. Euastrum ampullaceum Ralfs var. incavatum Turner

(Turner 1892, p. 78, pl. 10, f. 59)

[Pl. XXVIII, f. 476, 477]

Cells medium sized, narrowly elliptic in outline, 1.7-1.8 times longer than broad;

semicells truncate-pyramidal, the polar lobes short, slightly divergent, apex flat

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with rounded angles, median notch short, narrow; lateral margins concave,

diverging to the polar lobes; basal lobes broad, slightly bi-lobed; sinus deep, ‘V’-

shaped; face of the semicells with 6 protuberances, just below the polar and basal

lobes; cell wall smooth.

Length: 65-67 µm, Breadth: 36-38 µm, Isthmus: 22-23 µm.

Collection No. DD-380, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with green scum in a swamp (pH 6, temp. 10ºC).

Indian distribution: Eastern India (Turner 1892).

This is the first report of the taxon from Eastern Himalaya.

2. Euastrum ansatum Ehrenberg ex Ralfs var. ansatum

(Krieger 1937, p. 485, pl. 58, f. 1-3; Prescott et al 1977, p. 15, pl. 63, f. 6, 6a, 7f,

8; Lenzenweger 1996, p. 74, pl. 9, f. 1)

[Pl. XXVIII, f. 475]

Cells medium sized, narrowly oval in shape, about 2 times longer than broad;

semicells triangular shaped; sinus closed, deep; basal angles broadly rounded,

lateral margins then converging to a truncate apex with rounded angles; apical

notch short and closed; cell wall finely punctate; face of the semicells with 3 small

protrusions at the base.

Length: 70-72 µm, Breadth: 34-36 µm, Isthmus: 16-16 µm.

Collection No. DD-380, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with green scum in a swamp (pH 6, temp. 10ºC).

Indian distribution: Eastern India (Turner 1892); West Bengal (Mukherjee &

Srivastava 1993); Muriyad, Kerala (Sanilkumar & Thomas 2006); Goalpara,

Assam (Deca et al. 2011).

3. Euastrum ansatum Ehrenberg ex Ralfs var. dideltiforme Ducellier

(West & GS West 1905, p. 27, pl. 36, f. 10-13; Krieger 1937, p. 488, pl. 58, f. 8;

Prescott et al. 1977, p. 17, pl. 59, f. 15, 15a)

[Pl. XXVIII, f. 472]

Cells medium sized, narrowly oval in outline, about 2 times longer than broad;

semicells triangular-pyramidal in shape, sinus closed, dilated at the extremities,

deep; basal angles broadly rounded, lateral margins forming low, rounded lateral

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lobes, then converging to flat apex with rounded angles; apical notch short,

narrow; face of the semicells with 3 low basal swellings and one mucilage pore on

either side at the midregion; cell wall finely punctate.

Length: 84-86 µm, Breadth: 44-46 µm, Isthmus: 9-10 µm.

Collection No. DD-380, 06.11.2009 Bitang-cho Lake, Sikkim. In association with

green scum in a swamp (pH 6, temp. 10ºC).

Indian distribution: Madhya Pradesh (Agarkar et al. 1979); West Bengal

(Mukherjee & Srivastava 1993).

This is the first report of the taxon from Eastern Himalaya.

4. Euastrum bidentatum Nageli var. oculatum (Istvanffi) Krieger

(Krieger 1937, p. 603, pl. 85, f. 7; Prescott et al. 1977, p. 22, pl. 77, f. 9)

[Pl. XXVIII, f. 478]

Cells medium sized; broadly oval in outline, 1.5 times longer than broad;

semicells semicircular; isthmus deep, sinus closed; lateral margins undulate, basal

lobes bi-lobed, upper basal lobules slightly produced than the lower one and

posses blunt tooth-like projection; upper lobes rounded, less produced, short,

apical angles extended into similar tooth-like process, apical margins broad,

slightly convex and undulate, apical notch short, angularly open; lateral margins

between upper and basal lobes retuse; face of the semicells with median bulging

bearing several large granules in circular arrangement; mucilage pores present

above the granules; cell wall otherwise smooth.

Length: 55-62 µm, Breadth: 34-39 µm, Isthmus: 12-14 µm.

Collection No. DD-379, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with deep green filamentous mass floating freely on the surface of water bloom

(pH 6, temp. 10ºC).

Indian distribution: This is probably the first report of the taxon from India.

5. Euastrum ciastonii Raciborski var. ciastonii

(Krieger 1937, p. 607, pl. 84, f. 16-18; Prescott et al. 1977, p. 31, pl. 78, f. 6, 6a)

[Pl. XXVIII, f. 479, 480]

Cells medium sized, rectangular in outline, 1-1.5 times longer than broad; basal

lobes broadly rounded with several small teeth, lateral margins retuse to the polar

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lobes which is slightly inflated, apical margin slightly elevated to a deep and

narrow median incision, apical angles with a short, sharp spine; face of the

semicells with 2 circles of 4 granules; both the upper and lower lobes having a

patch of sub-marginal granules; isthmus deep, sinus angular, open; rest of the cell

wall smooth.

Length: 42-44 µm, Breadth: 29-32 µm, Isthmus: 6-7 µm.

The present specimen appears more or less close to the type.

Collection No. DD- 419, 06.11.2009, Mamencho Lake, Sikkim. In association

with greenish-yellow filaments on the surface of the water (pH 6, temp. 10ºC).

Indian distribution: This is probably the first report of the taxon from India.

6. Euastrum denticulatum (Kirchner) Gay var. denticulatum f. glabrum Prescott

(Prescott et al. 1977, p. 40, pl. 75, f. 7f)

[Pl. XXVIII, f. 488, 489]

Cells small, about 1.5 times longer than broad, sub-rectangular in outline; sinus

moderate, closed; semicells truncate-pyramidal in shape; basal lobes broad with

undulate margins; apical lobes short with subparallel margins, less prominently

produced than the typical, apex truncate, angles narrow, furnished with a short

spine, upper median notch small, angularly open, upper lateral margins undulate;

face of the semicells with low median swelling with a mucilage pore; cell wall

smooth.

Length: 22-23 µm, Breadth: 15-16 µm, Isthmus: 7-9 µm.

Collection No. DD-389, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with light green filaments on the surface of the water (pH 6, temp. 10ºC).

Indian distribution: This is probably the first report of the taxon from India.

7. Euastrum denticulatum (Kirchner) Gay var. quadrifarium Krieger

(Krieger 1937, p. 585, pl. 80, f. 20, 21; Prescott et al. 1977, p. 42, pl. 75, f. 9)

[Pl. XXVIII, f. 483, 484]

Cells small, 1.5-1.6 times longer than broad, sub-rectangular in outline, semicells

sub-quadrate; sinus closed; basal lobes little undulate, parallel; lateral margins

with a median notch, apical lobes slightly produced, angles with a short, blunt

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spine; apex flat, upper median sinus deep, angular; upper basal lobes with small

granules; face of the semicells with 4 small granules, one in each lobe.

Length: 25-26 µm, Breadth: 16-17 µm, Isthmus: 4-5 µm.

Collection No. DD-585, 12.11.2009, Namchi, Sikkim. With phytoplankton

sample collected from a small waterfall (pH 6.5, temp. 15ºC).

Indian distribution: Kerala (Shaji et al. 1988); Pithoragarh (Chaturvedi & Habib

1993).

This is the first report of the taxon from Eastern Himalaya.

8. Euastrum diplostauron Skuja

(Skuja 1949, p. 112; Ling & Tyler 1986, p. 27, pl. 18, f. 28)

[Pl. XXVIII, f. 485, 486]

Cells small, 1-1.2 times broader than long, shaped transversely quadrate; isthmus

deep, sinus open, broad; semicells with much produced basal lobes, horizontally

directed and furnished with several short, blunt teeth, slightly divergent; polar

lobe short, much reduced, angles narrow, apex flat, 3-undulate; face of the

semicells with a central circle of 4 granules, relatively small granules present just

below the basal lobes, usually 3 in number; cell wall otherwise smooth.

Length: 20-21 µm, Breadth: 24-25 µm, Isthmus: 6-7 µm.

Collection No. DD-583, 12.11.2009, Namchi, Sikkim. In association with

greenish-brown scum with mosses on a small rock pool (pH 6.5, temp. 14ºC).

Indian distribution: This is probably the first report of the taxon from India.

9. Euastrum humerosum Ralfs

(West & GS West 1905, p. 8, pl. 34, f. 1, 2; Krieger 1937, p. 524, pl. 69, f. 4-6;

Prescott et al. 1977, p. 63, pl. 63, f. 7, 7a; Lenzenweger 1996, p. 83, pl. 9, f. 12)

[Pl. XXVIII, f. 463]

Cells large, broadly oval in outline, above 2 times longer than broad; sinus deep,

closed; semicells sub-pyramidal in outline; basal lobes bi-lobed with broadly

rounded angles; lateral margins retuse, forming ‘U’-shaped notch, then

converging into 2 lateral lobules somewhat upwardly directed and again forming a

narrow notch then forming broad convex apex with relatively narrowly rounded

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apical angles, apical notch short, closed; face of the semicells with a broad basal

swelling downwardly directed; cell wall finely punctate.

Length: 148-157 µm, Breadth: 68-74 µm, Isthmus: 15-18 µm.

Collection No. DD-415, 06.11.2009, Mamencho Lake, Sikkim. In association

with greenish-brown scum attached to the surface of the wet rock (pH 6, temp.

10ºC). DD-470, 09.11.2009, Rimbi river, Sikkim. In association with dark brown

scum submerged in a rock pool beside the river (pH 6, temp. 10ºC).

Indian distribution: Eastern India (Turner 1892).

This is the first report of the taxon from Eastern Himalaya.

10. Euastrum lütkemülleri Ducellier var. lütkemülleri

(Krieger 1937, p. 560, pl. 80, f. 1-4; Prescott et al. 1977, p. 81, pl. 72, f. 2, 2a;

Lenzenweger 1996, p. 85, pl. 10, f. 19)

[Pl. XXVIII, f. 490, 491]

Cells small, truncate oval in outline, 1.5 times longer than broad; semicells

truncate-pyramidal, the basal lobes narrowly rounded at the angles, the margins

retuse and converging to the apex; polar lobe scarcely evident; angles of the polar

lobe bluntly pointed, the apical margin flat but retuse at the midregion; face of the

semicells with a broad, low protuberance; sinus narrow and low throughout;

lateral margins retuse at the midregion; cell wall smooth.

Length: 10-12 µm, Breadth: 15-17 µm, Isthmus: 6-7 µm.

Collection No. DD-380, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with green scum in a swamp (pH 6, temp. 10ºC).

Indian distribution: Madhya Pradesh (Agarkar 1971).

This is the first report of the taxon from Eastern Himalaya.

11. Euastrum obesum Jashua var. subangulare West et GS West

(Krieger 1937, p. 497, pl. 59, f. 14; Prescott et al. 1977, p. 84, pl. 60, f. 5, 5a, 10)

[Pl. XXVIII, f. 473, 474]

Cells medium sized, narrowly elliptic in outline; above 2 times longer than broad;

sinus deep, closed; semicells pyramidal with truncate apex; basal lobes narrowly

rounded, apical angles rounded, median notch short, narrow; lateral margins

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retuse slightly then converging at the apex; median swelling less prominent; cell

wall smooth.

Length: 84-87 µm, Breadth: 38-40 µm, Isthmus: 10-11 µm.

Collection No. DD-71, 17.04.2009, Legship, Sikkim. In association with black

scum on the rocks under the stream (pH 5, temp. 23ºC).

Indian distribution: This is probably the first report of the taxon from India.

12. Euastrum oblongum (Greville) Ralfs

(West & GS West 1905, p. 12, pl. 34. f. 7-9, pl. 15, f. 2; Krieger 1937, p. 527, pl.

70, f. 7, 8; Prescott et al. 1977, p. 84, pl. 65, f. 4; Lenzenweger 1996, p. 86, pl. 10,

f. 4)

[Pl. XXVIII, f. 462]

Cells large, broadly oval in outline, about 2 times longer than broad; semi cells

broadly oval in outline with a broad, truncate base; basal lobe sub-rectangular at

the margin, bi-lobed and shoulder-like, a deep incision between the basal lobe and

a bi-lobed upper lateral lobule and a narrow, deep incision between the upper

lateral lobules and the polar lobe; polar lobe anvil-shaped, the angles narrowly

rounded; the apical margin convex, with a deep, narrow median incision; sinus

narrow and closed; face of the semicells with a supra-isthmial protuberance near

the mid region of the semicell, with a central mucilage pore.

Length: 186-190 µm, Breadth: 100-103 µm, Isthmus: 38-39 µm, Apex: 54-61 µm.

Collection No. DD-416, 06.11.2009, Mamencho Lake, Sikkim. In association

with brownish scum attached to the surface of the submerged part of the semi

aquatic plants (pH 6, temp. 10ºC). DD-408, 06.11.2009, Changu Lake, Sikkim. In

association with dark green mat like structure on the surface of the water (pH 6,

temp. 9ºC).

Indian distribution: Kashmir (Suxena & Venkateswarlu 1968b); Bareilly, Uttar

Pradesh (Habib 1994).

This is the first report of the taxon from Eastern Himalaya.

13. Euastrum platycerum Reinsch var. eximium Gronblad et Scott f. clausum

Gronblad et Scott

(Prescott et al. 1977, p. 95, pl. 81, f. 9)

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[Pl. XXVIII, f. 464, 465]

Cells medium sized, 1-1.25 times longer than broad; isthmus deep, sinus narrow,

open outwardly with small extensions of the basal lobes which is broadly rounded;

the lateral margins having shoulder-like incision between the basal and polar lobes

which is slightly divergent; apical angles narrowly rounded and furnished with

short blunt spines; apical margins slightly retuse in the midregion, basal lobes

with similar short spines greater in number; face of the semicells with a circle of

small granules; cell wall with a scattering of granules just below the apical and

basal lobes; cell wall otherwise smooth.

Length: 43-46 µm, Breadth: 41-45 µm, Isthmus: 8-9 µm.

The present specimen is bit smaller than the type.

Collection No. DD-379, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with Deep green filamentous mass floating freely on the surface of water bloom

(pH 6, temp. 10ºC).

Indian distribution: This is probably the first report of the taxon from India.

14. Euastrum pseudocorralloides Fritsch

(Krieger 1937, p. 587, pl. 81, f. 1-3; Prescott et al. 1977, p. 98, pl. 74, f. 25)

[Pl. XXVIII, f. 487]

Cells small, nearly rectangular in outline, 1-1.3 times longer than broad; semicells

sub-quadrate in outline, basal lobes bi-lobed, rounded; lateral margins retuse

deeply then formed little divergent upper lobes, lateral angles of upper lobes with

single mucro; apical margins slightly convex with a shallow ‘V’-shaped median

notch; face of the semicells with a small median protuberance; cell wall smooth;

sinus narrow, closed, isthmus deep.

Length: 25-29 µm, Breadth: 22-23 µm, Isthmus: 5-8 µm.

Collection No. DD-396, 06.11.2009, Babamandir, Sikkim. In association with

mosses on the rocks under the water (pH 6, temp. 8ºC).

Indian distribution: This is probably the first report of the taxon from India.

15. Euastrum spinulosum Delponte var. spinulosum

(Krieger 1937, p. 633, pl. 93, f. 1-3; Prescott et al. 1977, p. 107, pl. 81, f. 10)

[Pl. XXVIII, f. 466, 467]

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174

Cells medium sized, nearly circular in outline, 1-1.2 times longer than broad;

semicells broadly oval transversely, basal angles broadly rounded and produced;

margins with a sinus between the basal lobes and equal sized upper, lateral lobes,

with a short crown like polar lobe, the angles rounded, the apical margins slightly

retuse in the midregion, margins of all the lobes with short, sharp spine like

granules and with patterns of similar spines on the face of the lobules; face of the

semicells with a broad central protuberance bearing a circular pattern of large

granules; wall smooth otherwise; sinus narrow and closed within, opening slightly

at the outer extremities.

Length: 40-59 µm, Breadth: 34-51 µm, Isthmus: 9-13 µm.

Collection No. DD-379, DD-381, 06.11.2009, Bitang-cho Lake, Sikkim. In

association with deep green filamentous mass floating freely on the surface of

water bloom (pH 6, temp. 10ºC). DD-788, 10.11.2011, Lolegaon, West Bangal.

Wet blakish brown powdery mass on the bark of a tree (pH 6, temp. 10ºC).

Indian distribution: Vidarbh, Maharashtra (Kamat 1975); Marathwada,

Maharashtra (Asthekar & Kamat 1979); Allahabad, Uttar Pradesh (Pandey &

Pandey 1980); Kashmir (Compère 1983); Udalkachar, Madhya Pradesh (Habib

1991); Nagpur, Maharashtra (Tarar et al. 1998); Shillong, Meghalaya (Gupta

2002); Siddharth Nagar, Uttar Pradesh (Prakash et al. 2005); Uttarakhand (Misra

et al. 2007); Jalgaon, North Maharashtra (Mahajan & Nandan 2008); Amarkantak,

Madhya Pradesh (Suseela & Toppo 2010); Goalpara, Assam (Deca et al. 2011);

Kangra, Himachal Pradesh (Kumar et al. 2012).

16. Euastrum spinulosum Delponte var. lindae Gronblad et Scott

(Prescott et al. 1977, p. 108, pl. 82, f. 8)

[Pl. XXVIII, f. 468, 469]

Cells medium sized, nearly quadrate in shape, 1.2-1.3 times longer than broad;

sinus closed, deep; basal angles narrowly rounded and produced; lateral margins

retuse forming ‘V’-shaped notch and forming narrowly rounded lateral lobes,

upwardly directed; apical lobes more produced than the typical; narrow, angular

sinus between the polar and lateral lobes; apex slightly retuse near the midregion;

all of the lobes furnished with several short blunt spines, face of the lobes also

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bear similar spines scatteredly disposed; face of the semicells with a median circle

of granules stacked on a low protuberance; cell wall otherwise smooth.

Length: 63-67 µm, Breadth: 48-53 µm, Isthmus: 13-15 µm.

Collection No. DD-389, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with light green filaments on the surface of the water (pH 6, temp. 10ºC).

Indian distribution: This is probably the first report of the taxon from India.

17. Euastrum subhypochondrum Fritsch et Rich

(Coesel 2000, p. 264, f. 2E, 3E, 4K)

[Pl. XXVIII, f. 470, 471]

Cells medium sized; slightly longer than broad; isthmus deep, sinus narrowly ‘V’-

shaped; basal lobes rounded, produced, horizontally directed; lateral margins with

deep, right angled shoulder-like incision between basal and apical lobes; apical

margins slightly undulate, apical angles narrow, bearing 2 stout blunt spines; basal

lobes bears similar spines but greater in numbers; small granules scatterdly

deposited on the terminal face of basal and apical lobes; face of the semicells with

a median circle of slightly broad granules in two concentric series and 2 relatively

small circular patch of small granules on either side of each basal lobes; cell wall

smooth otherwise.

Length: 50-55 µm, Breadth: 47-50 µm, Isthmus: 14-15 µm.

Collection No. DD-26, 16.04.2009, Pelling, Sikkim. In association with blue-

green mass in a drain (pH 5.5, temp. 21ºC).

Indian distribution: This is probably the first report of the taxon from India.

18. Euastrum turnerii West var. turnerii

(West & GS West 1905, p. 37, pl. 37, f. 9, 10; Krieger 1937, p. 91, pl. 11, f. 22, p.

589, pl. 82, f. 20, 21; Prescott et al. 1977, p. 113, pl. 75, f. 16)

[Pl. XXVIII, f. 481, 482]

Cells small, truncate-oval in outline, 1-1.3 times longer than broad; semicells

truncate-pyramidal in shape, basal angles bi-undulate, lateral walls retuse in the

midregion then converging to polar lobes; upper lateral angles with single short

stout spine; lateral lobules bears small spines; apical margins flat containing a

median ‘U’-shaped sinus; face of the semicells with a median protuberance

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bearing a circle of 3 median sized granules; basal and apical lobes each bears

several small granules; cell wall smooth.

Length: 29-32 µm, Breadth: 23-25 µm, Isthmus: 3-4 µm.

Collection No. DD-35, 16.04.2009, Pelling, Sikkim. With phytoplankton sample

collected from a small Lake (pH 5, temp. 20ºC). DD-846, 12.11.2011, Chage falls,

Lava. With phytoplankton sample collected from the falls (pH 6, temp. 17ºC).

Indian distribution: Vidarbh, Maharashtra (Kamat 1975); Goalpara, Assam

(Deca et al. 2011).

VII. Genicularia de Bary

Cells solitary, sometimes loosely attached end to end immediate after dividing

forming short filament, cylindrical, elongate with truncate apices. Median constriction

absent, cell wall minutely granulate. Chloroplast 2-3, parietal, narrow, spiral bands,

pyrenoids numerous, lying in a series.

1. Genicularia elegans West et GS West

(West & GS West 1904, p. 36, pl. 5, f. 1, 2; Prescott et al. 1972, p. 32, pl. 6, f. 31,

32)

[Pl. XXVII, f. 453, 454]

Cells cylindrical, straight, elongate, 23-38 times longer than broad; lateral walls

parallel, slightly diverging near the apex; apex broadly truncate, cell wall smooth;

chloroplast 2, parietal, spirally coiled bands, pyrenoids 8, in a series.

Length: 151-185 µm. Breadth: 4-8 µm. Apex: 5-9 µm.

Collection No. DD-380, 06.11.2009, Bitang-cho Lake Sikkim. In association with

greenish-yellow filaments on the surface of the water forming scum (pH 6, temp.

10ºC). DD-12, 16.04.2009, small Lake, Pelling. With phytoplankton samples

collected from the Lake (pH 5, temp. 19ºC).

Indian distribution: This is probably the first report of the taxon from India.

VIII. Gonatozygon de Bary

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Cells solitary, medium sized to large, cylindrical, to narrowly fusiform (7-40 times

longer than broad) with truncate to sub-capitate apex. Lateral wall nearly parallel,

sometimes slightly diverging toward the apex. Cell wall smooth or with scattered

granules, setae or spines, nearly with girdle bands. Cell wall two layered. Chloroplast

single in each semicell, axial, ribbon-like with a row of 4-16 pyrenoids.

Key to the taxa investigated:

1. Cells without spines

2. Cell wall punctate

2. Cell wall smooth..…………………………….…….……………(2) G. kinahani

3. Cells stout, 15-16 µm broad, 9-10 tomes longer than broad

……(4)G. monotaenium var. monotaenium f. punctatum

3. Cells relatively slender, 7-8 µm broad, more than 10 times (12-14 times)

longer than broad…...…...(3) G. monotaenium var. monotaenium f. minutum

1. Cell wall with short hair-like spines…..……………………………(1) G. aculeatum

1. Gonatozygon aculeatum Hastings

(Prescott et al. 1972, p. 33, pl. 8, f. 13-15; Lenzenweger 1996, p. 15, pl. 1, f. 3)

[Pl. XXVII, f. 457]

Cells medium sized, cylindrical, 12-17 times longer than broad; lateral wall

straight, parallel only very slightly diverging at the poles; apices truncate but

slightly dilated with the apical angles slightly rounded; cell wall densely covered

with small, sharp, erect spines but poles are spine-less; chloroplast axial with 7

pyrenoids.

Length: 114-116 µm, Breadth: 7-9 µm, Apex: 9-10 µm.

Collection No. DD-490, 09.11.2009 Khechiperi Lake, Sikkim. In association with

green filaments growing attached on pebbles & submerged weeds (pH 6.5, temp.

14°C).

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Indian distribution: Vidarbh, Maharashtra (Kamat 1975); Allahabad (Pandey &

Pandey 1980); Karnataka and Goa (Bharti & Hegde 1982a); Kalimpong (Santra &

Pal 2006).

2. Gonatozygon kinahani (Archer) Rabenhorst

(West & GS West 1904, p. 35, pl. 2, f. 1-3; Prescott et al. 1972, p. 35, pl. 7, f. 1-4;

Lenzenweger 1996, p. 16, pl. 1, f. 1)

[Pl. XXVII, f. 460, 461]

Cells cylindrical, slightly curved, 11-12 times longer than broad; apices truncate,

angles rounded; lateral margins parallel; chloroplast with 6 longitudinal ridges, 10

pyrenoids in a series; cell wall smooth, colourless.

Length: 192-198 µm, Breadth: 16-17 µm, Apex: 16-18 µm.

Collection No. DD-212, 10.05.2009, Changu Lake, Sikkim. In association with

submerged weeds growing beside the Lake (pH 6, temp 6ºC). DD-111,

18.04.2009, Khechiperi Lake, Sikkim. In association with light green filaments

floating freely on the surface of the water (pH 6, temp 10ºC). DD-756,

10.11.2011, Lava, West Bengal. In association with green filaments floats freely

on the surface of a small water body (pH 6, temp 17ºC) .

Indian distribution: Kodaikanal, Tamilnadu (Iyengar & Vimla Bai 1941);

Vidarbh, Maharashtra (Kamat 1975); Savandurga, Karnataka (Gurudeva et al.

1983); Rohilkhand, Uttar Pradesh (Habib 1993); Pilibhit, Uttar Pradesh (Habib

1997); Muriyad, Kerala (Sanilkumar & Thomas 2006); Kalimpong (Santra & Pal

2006); Eastern Himalaya (Yasmin et al. 2011).

3. Gonatozygon monotaenium de Bary var. monotaenium f. minutum Cushman

(Prescott et al. 1972, p. 36,)

[Pl. XXVII, f. 455, 456]

Cells small, cylindrical, 11-12 times longer than broad; lateral wall parallel and

straight; apex broadly rounded; cell wall minutely and densely granular, granules

irregularly arranged and variable; chloroplast axial, pyrenoids 7 in number.

Length: 105-112 µm, Breadth: 9-10 µm, Apex: 6-8 µm.

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Collection No. DD-490, 09.11.2009, Khechiperi Lake, Sikkim. In association

with green filaments growing attached on pebbles & submerged weeds (pH 6.5,

temp. 14°C).

Indian distribution: This is probably the first report of the taxon from India.

4. Gonatozygon monotaenium de Bary var. monotaenium f. punctatum Croasdale

(Prescott et al. 1972, p. 36, pl. 7, f. 13)

[Pl. XXVII, f. 458, 459]

Cells stout, 9-10 times longer than broad, cylindrical; lateral wall parallel, straight;

apex truncate-rounded; chloroplast single, axial plate with 7 pyrenoids; cell wall

punctate.

Length: 145-148 µm, Breadth: 15-16 µm, Apex: 16-18 µm.

Collection No. DD-418, 06.11.2009, Mamencho Lake, Sikkim. In association

with light green filaments floats freely on the water (pH 6, temp 10ºC).

Indian distribution: This is probably the first report of the taxon from India.

IX. Haplotaenium Bando

Cells solitary, cylindrical, elongate with a slightly constricted in the middle; semicells

with very slight basal swelling or sometimes absent; apex truncately rounded, rarely

retuse; cell apex without terminal vacuoles or any granules; cell wall generally

smooth or finely punctate. Chloroplast single, axial or band-like with irregular

longitudinal lamellae having 2-15 pyrenoids arranged in a central row.

1. Haplotaenium minutum (Ralfs) Bando var. gracile (Wille) Bando

(Bando 1988, p. 25, f. 14, 36)

[Pl. XXVII, f. 452]

Cells cylindrical, solitary, elongate, 16-18 times longer than broad; median

constriction very slight, having a minute notch; lateral margins parallel and very

slightly tapering at the apex, apex rounded-truncate; cell wall minutely punctate,

punctae arranged in oblique series.

Length: 181-184 µm, Breadth: 10-11 µm, Apex: 9-10 µm.

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Collection No. DD-588, 12.11.2009, Namchi, Sikkim. In association with aquatic

weeds attached on the wet rock beside a small water fall (pH 6.5, temp. 15ºC).

Indian distribution: This is probably the first report of the taxon from India.

X. Hyalotheca Ehrenbarg ex Ralfs

Cells cylindrical or sub-cylindrical, united to form un-branched filament by their

broad truncated apices, filaments sometimes twisted and sometimes embedded in a

broad gelatinous sheath. Cells very slightly constricted at the middle or sometimes

constriction absent. Semicells trapezoid, sub-quadrate or transversely oblong with

straight or slightly convex lateral margins. Chloroplast axial, single with median

pyrenoid in each semicells. Cell wall smooth or having granules.

Key to the taxa investigated:

1. Cells constricted in the middle, cell wall not having any ornamentation

2. Sinus an acute notch.....................................................(2) H. dissiliens var. hians

2. Sinus with very slight annular depression.............(1) H. dissiliens var. dissiliens

1. Cells not constricted in the mid-region, with 2 parallel transverse series of tiny

granules immediately beneath the apex of the semicells.....................(3) H. mucosa

1. Hyalotheca dissiliens (Smith) Brébisson ex Ralfs var. dissiliens f. dissiliens

(West et al. 1923, p. 229, pl. 156, f. 16-27; Croasdale et al. 1983, p. 28, pl. 460, f.

6-12; Lenzenweger 1997, p. 140, pl. 43, f. 1, 2)

[Pl. XXVII, f. 440-443]

Cells united by broadly truncate apices to form long filamentous colonies; cells of

the colony are small, 14-17 µm long 26-29 µm broad, very faintly constricted,

sinus showing as a very slightly annular depression in the middle of the lateral

margins; semicells cylindrical-discoidal, the lateral margin slightly convex, the

apices broadly truncate; semicells in vertical view cylindrical; chloroplast axial,

one in each semicell, usually with a central pyrenoid, and several radiating ridges

flattened at extremities, greenish-brown in colour.

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Length: 14-17 µm, Breadth: 26-29 µm, Isthmus: 25-27 µm.

No. DD-413, 06.11.2009, Mamencho Lake, Sikkim. In association with light

greenish-yellow filaments attached on the surface of the wet rock (pH 6, temp

10ºC). DD-777, 10.11.2011, Lolegaon, West Bengal. In association with

mucilaginous masses growing on the wet rocks (pH 6, temp. 20ºC).

Indian distribution: Eastern India (Turner 1892); Kodaikanal, Tamilnadu

(Iyengar & Vimla Bai 1941); Vidarbh, Maharashtra (Kamat 1975); Madhya

Pradesh (Agarker & Agarkar 1977); Marathwada, Maharashtra (Asthekar &

Kamat 1979); Nagpur (Freitas & Kamat 1979); Kashmir (Compère 1983);

Shillong, Meghalaya (Rout & Gaur 1994); Nagpur, Maharashtra (Tarar et al.

1998); Sikkim, Kalimpong (Santra & Pal 2006); Goalpara, Assam (Deca et al.

2011); Mamencho Lake, Sikkim (Das & Keshri 2012).

2. Hyalotheca dissiliens Brébisson var. hians Wolle

(West et al. 1923, p. 234, pl. 157, f. 16-18; Croasdale et al. 1983, p. 29, pl. 461, f.

2, 3)

[Pl. XXVI, f. 438, 439]

Cells small, 1.6-2 times broader than long; sinus showing an acute median incision

or notch in the middle of the lateral margins; semicells cylindrical-discoidal,

lateral margins convex, the apices broadly truncate, semicells in vertical view

circular; cells attached loosely end to end forming long filaments, filament

conspicuously constricted at the joints; chloroplast axial, with several radiating

ridges.

Length: 16-18 µm, Breadth: 25-27 µm, Isthmus: 25-26 µm, Thickness: 25-27 µm.

Collection No. DD-379, 06.11.2009, Khechiperi Lake, Sikkim. In association

with green filaments on the surface of the water (pH 6, temp 10ºC).

Indian distribution: Nagpur, Maharashtra (Tarar et al. 1998).

This is the first report of the taxon from Eastern Himalaya.

3. Hyalotheca mucosa (Mertins) Ehrenberg ex Ralfs

(West et al. 1923, p. 235, pl. 157, f. 1-4; Croasdale et al. 1983, p. 30, pl. 461, f. 6-

8; Lenzenweger 1997, p. 141, pl. 43, f. 5)

[Pl. XXVII, f. 444, 445]

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Cells small, slightly longer than broad, attached end to end to form short filament;

devoid of any indication of constriction, very slightly constricted at the joints;

semicells transversely sub-rectangular, lateral margins nearly parallel, very

convex with upper angles broadly rounded; apex broad and truncate; cell wall

smooth except 2 parallel, transverse series of tiny granules just beneath the apices.

Length: 15-18 µm, Breadth: 12-14 µm.

The present specimen tallies in some respect with H. laevicinata Taylor. It appears

that such forms are intermediate between H. mucosa & H. laevicinata. However

since the form is closer to H. mucosa it has been placed in it.

Collection No. DD-384, 05.11.2009, Bitang-cho Lake Sikkim. In association with

aquatic weeds submerged in the water (pH 6, temp 10ºC).

Indian distribution: Eastern India (Turner 1892); Vidarbh, Maharashtra (Kamat

1975).

This is the first report of the taxon from Eastern Himalaya.

XI. Micrasterias Agardh ex Ralfs

The genus Micrasterias is characterized by relatively flattened disc and radiating often

having deeply dissected lobes, showing bilateral and bipolar symmetry. A deep,

usually narrow, sometimes open median sinus divides the cell into two semicells,

which are again divided into 3 lobes: a polar lobe and 2 lateral lobes. The polar lobe

forms the apex of the cell and may be at its summit, flat, slightly rounded, depressed

or shallowly notch, but it is not further divided, although its upper lateral extremities

may be variously drawn out, not processes which are sometimes referred to as polar

lobes or lobules. In case of M. foliacea cells are united by the interlocking of the polar

lobes forming filaments. The lateral lobes are in most species are divided into lobules

and are vary in the angles and number of incisions, in some species the incisions are

horizontal, parallel to the sinus but in majority of species the incisions are radial. The

first divisions of a lateral lobe results in an upper and lower lateral lobules, this

referred to as ‘once divided’ or ‘first order division’. In many cases these lobules are

again divided into further smaller and shallower incisions described respectively as

‘second order division’, ‘third order division’ and so on. The divided processes shape

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varies from stout to narrow, long to short etc. and ultimate divisions are usually

excavated or uni-dentate to tri-dentate or some other conditions may exist.

The cells are filled although not entirely with a single axial lobed chloroplast centered

by a single nucleus at the center of the cell, opposite both the sinus and show several

to many pyrenoids scattered into the chloroplast. The chloroplast is not extended to

the inner end wall of each process.

The cell walls are always thin, bi-layered. In maximum species cell wall smooth,

sometimes with granules, scrobicules, punctae or even teeth on the outer margin of

the cell wall is present.

Semicells in vertical view are generally narrowly fusiform, sometimes showing a

small central protuberance; in lateral view cells narrowly tapering from a slightly

swollen median portion.

Key to the taxa investigated:

1. Polar lobes broad, without well marked median incision, apex sometimes slightly

retuse

2. Polar lobe with accessory processes…….…………….(5) M. mahabuleswarensis

2. Polar lobe without accessory processes.

3. Apex retuse, cell wall with marginal spines…………...………..(8) M. tropica

3. Apex flatly convex, cell wall smooth

4. Lateral lobes truncate, furnished with single spine, downwardly directed

…………………...….…(9) M. zeylanica

4. Lateral lobes swollen at the base, then converging into two upwardly

directed teeth……………………………………...……...(6) M. pinnatifida

1. Polar lobes less broad with median incision of variable depth, apex strongly retuse

5. Lateral lobes once divided, apical and lateral angles furnished with with long,

blunt spines……………………………………………………..(3) M. ceratofera

5. Lateral lobes more than once divided, apical and lateral angles with processes,

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sometimes denticulate, rather with spines

6. Cells square in outline; lateral lobes divided more than second order, united in

filaments by the interlocking of the polar lobes…………......…(4) M. foliacea

6. Cells more or less circular in outline, lateral lobes divided twice, not united

into filaments

7. Secondary lateral incisions deep, extending more than halfway than the

sinus, lobules swollen at the base, then abruptly and narrowly tapering to

tri-dentate extremities

8. Cell wall smooth, shorter, 104-108 µm in length…………….(1) M. alata

8. Cell wall granulate, longer, 126-130 µm in length…....(2) M. alata forma

7. Secondary lateral incision moderately deep, extending not more than

halfway than sinus, ultimate lateral lobules stout, terminating in paired

teeth……………………………………………………..…..(7) M. radians

1. Micrasterias alata Wallich

(Krieger 1939, p. 61, pl. 114, f. 1-4; Prescott et al. 1977, p. 138, pl. 112, f. 3-8)

[Pl. XXIX, f. 505; pl. XXX, f. 506]

Cells medium sized; sinus deep, closed in inner quarter, then widely open; lateral

lobes once divided, the lower member simple, all divisions deep; lobules swollen

at the base, then abruptly and narrowly tapering to tridentate extremities, the upper

margin of the upper member extending vertically, parallel to the polar lobe,

separated from it by a deep and narrow incision; polar lobe slender with parallel

sides, abruptly branching at apex into 2 slender diverging processes; cell wall

smooth.

Length: 104-145 µm, Breadth: 111-133 µm, Isthmus: 16-18µm.

Collection No. DD-412, 06.11.2009, Mamencho Lake, Sikkim. In association

with green filaments growing attached on pebbles & submerged weeds (pH 6

temp. 10ºC). DD-726, 02.05.2010, Mach Pokhri, Kalimpong. In association with

light green filaments on the surface of the wet rock (pH 6.5 temp. 24ºC).

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Indian distribution: Eastern India (Turner 1892); West Bengal (Mukherjee &

Srivastava 1993).

This is the first report of the taxon from Eastern Himalaya.

2. Micrasterias alata Wallich forma

(Prescott et al. 1977, p. 138, pl. 112, f. 3-8)

[Pl. XXX, f. 507, 508]

Differs from the type in being larger and granules on the surface.

Length: 155-165 µm, Breadth: 137-141 µm, Isthmus: 15-16 µm, Breadth at the

apex: 52-55 µm.

Collection No. DD-412, 06.11.2009, Mamencho Lake, Sikkim. In association

with slimy mass growing benthic near the margins of the Lake (pH 6 temp. 10ºC).

3. Micrasterias ceratofera Joshua

(Ling & Tyler 1986, p. 30, pl. 22, f. 12)

[Pl. XXIX, f. 503, 504]

Cells large, elongate, about twice as long as broad; sinus deep, isthmus open,

acute angled; semicells pyramidal-hexagonal, basal lobes broad, once divided,

furnished with single, long, blunt spine, both spines directed oppositely; upper

lobe elongate, lateral margin very slight attenuate; apex retuse having two long,

blunt spines, slightly diverging; cell wall smooth.

Length: 168-171 µm, Breadth: 86-89 µm, Isthmus: 18-20 µm.

Collection No. DD-418, 06.11.2009, Mamencho Lake, Sikkim. In association

with green filaments on the surface of the water (pH 6, temp. 10ºC).

Indian distribution: Eastern India (Turner 1892).

This is the first report of the taxon from Eastern Himalaya.

4. Micrasterias foliacea Bailey ex Ralfs var. foliacea

(Krieger 1939, p. 77, pl. 120, f. 8, 9, pl. 121, f. 1-5; Prescott et al. 1977, p. 158, pl.

139, f. 3-8)

[Pl. XXIX, f. 499, 500; pl. XXX, f. 513, 514]

Cells moderate, occur singly or united in filaments by the interlocking of the polar

lobes; cells rectangular, slightly longer than broad; sinus sublinear; lateral lobes

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divided to the second and third order, dissimilar, the lower lobules horizontal, the

upper diverging, its upper part reduced to a conical projection; polar lobe very

distinctive, basal part narrow with erect parallel sides, upper three-quarters of the

lobe greatly expanded, with a very broad, deep subrectangular excavation in the

middle of the apex, angles stout, ending in 2 widely divergent teeth; depressed

portion of the apex bearing two stout spines on each side, unequal in size; semicell

in vertical view narrowly fusiform, the central part obliquely rhomboidal, showing

the unequal apical spines.

Length: 51-94 µm, Breadth: 58-77 µm, Isthmus: 15-22 µm.

Collection No. DD-382, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with light green filaments floating freely on the surface of the water (pH 6, temp.

8ºC). DD-411, 06.11.2009, Mamencho Lake, Sikkim. In association with aquatic

pebbles growing on the mud (pH 6, temp. 10ºC). DD-710, 01.05.2010, Delo

reservoir, Kalimpong. With the phytoplankton sample collected from the Lake

(pH 7, temp. 21ºC).

Indian distribution: Eastern India (Turner 1892); Assam (Carter 1926; Brhül &

Biswas 1926); Kodaikanal, Tamil Nadu (Bharati & Pai 1972); Vidarbh,

Maharashtra (Kamat 1975); Uttar Pradesh (Prasad & Mehrotra 1977a); Nagpur

(Freitas & Kamat 1979); Andaman (Prasad & Misra 1985); West Bengal

(Mukherjee & Srivastava 1993); Nagpur, Maharashtra (Tarar et al. 1998);

Siddharth Nagar (Prakash et al. 2005); Muriyad, Kerala (Sanilkumar & Thomas

2006); Bihar (Kumar & Chaudhary 2009); Goalpara, Assam (Deca et al. 2011).

5. Micrasterias mahabuleshwarensis Hobson var. mahabuleshwarensis

(Hobson 1863, p. 168, f. 169; West & GS West 1909, p. 121; Krieger 1939, p. 49,

pl. 109, f. 7-10; Prescott et al. 1977, p. 164, pl. 143, f. 1, 2, 4, 5; Dillard 1993, p.

94, pl. 12, f. 14)

[Pl. XXIX, f. 501, 502]

Cells of medium size, slightly longer than broad; sinus sharp angled, widely open;

polar lobe in lower half quadrate, above widely expanding into narrow diverging

processes at the angles, with more nearly erect accessory processes at their base,

arising asymmetrically, one at the front and one at the back of the apex, apex

between processes nearly straight; lateral lobes once divided into narrow tapering

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processes; all processes with serrate margins, ends tri-denticulate; semicells with a

row of acute intra-marginal granules along the inner part of the major incisions,

with a small granulate central protuberance above the isthmus.

Length: 110-115 µm, Breadth: 96-100 µm, Isthmus: 21-22 µm, Breadth at the

apex: 62-64 µm.

Collection No. DD-31, 16.04.2009, Pelling, Sikkim. In association with deep

green filaments floating freely on the surface of water forming bloom in a small

Lake (pH 5 temp. 21ºC).

Indian distribution: Eastern India (Turner 1892); Nagpur (Freitas & Kamat

1979); Andamans (Prasad & Misra 1982); Basti, Uttar Pradesh (Misra et al. 2001);

Uttar Pradesh (Misra & Srivastava 2003); Muriyad, Kerala (Sanilkumar &

Thomas 2006); Bihar (Kumar & Chaudhary 2009).

This is the first report of the taxon from Eastern Himalaya.

6. Micrasterias pinnatifida (Kützing) Ralfs var. pinnatifida

(West & GS West 1909, p. 80, pl. 41, f. 7-9, 13; Krieger 1939, p. 16, pl. 99, f. 6-9;

Prescott et al. 1977, p. 173, pl. 89, f. 6-8, pl. 90, f. 1-8; Lenzenweger 1996, p. 106,

pl. 13, f. 1)

[Pl. XXX, f. 515, 516]

Cells small, slightly longer than broad, deeply constricted, sinus closed; lateral

lobes single, undivided, conical, horizontally extended, somewhat constrict just

before the bifid extremity, polar lobes horizontally spreading, apex very slightly

convex; polar extension smaller than the lateral lobes, bifid at the extremities; sub-

polar incision deep and semicircular within; wall smooth; chloroplast with erect

curved lamellae having few pyrenoids.

Length: 50-63 µm, Breadth: 58-61µm, Isthmus: 7-9 µm.

Collection No. DD-382, DD-388, 09.11.2009, Khechiperi Lake, Sikkim. In

association with wet mosses on the bank (pH 6, temp. 10ºC). DD-408, 06.11.2009,

Changu Lake, Sikkim. With phytoplankton samples collected from the Lake (pH

6, temp. 9ºC). DD-804, 11.11.2011, Rishop, West Bengal. In association with

brown scum from a small water body (pH 6, temp. 10ºC).

Indian distribution: Eastern India (Turner 1892); Gwalior, Madhya Pradesh

(Agarkar 1969); Kodaikanal, (Iyengar & Vimla Bai 1941; Bharati & Pai 1972);

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Vidarbh, Maharashtra (Kamat 1975); Allahabad (Pandey & Pandey 1980);

Savandurga, Karnataka (Gurudeva 1983); Kashmir (Compère 1983); Andaman

(Prasad & Misra 1985); Rohilkhand, Uttar Pradesh (Habib 1993); Pilibhit, Uttar

Pradesh (Habib 1997); Basti, Uttar Pradesh (Misra et al. 2001); Shillong,

Meghalaya (Gupta 2002); Uttar Pradesh (Misra & Srivastava 2003); Uttarakhand

(Misra et al. 2008); Bihar (Kumar & Chaudhary 2009); Goalpara, Assam (Deca et

al. 2011); Eastern Himalaya (Yasmin et al. 2011).

7. Micrasterias radians Turner

(Turner 1892, p. 91, pl. 5, f. 6a; Krieger 1939, p. 67, pl. 115, f. 8, pl. 116, f. 1;

Prescott et al. 1977, p. 176, pl. 115, f. 5-7)

[Pl. XXX, f. 509, 510]

Cells large, about 1.3 times longer than broad; lateral lobes evenly twice divided,

lobules slightly swollen at the base, terminating in paired teeth; polar lobe slightly

exerted, the lower margins parallel, the upper part diverging, the apex deeply

concave between the 2 short bi-dentate processes, all incision widely open; cell

wall smooth.

Length: 155-162 µm, Breadth: 118-122 µm, Isthmus: 26-27 µm.

Collection No. DD-383, 06.11.2009, Bitang-cho Lake Sikkim. Brownish scum

lodged on the submerged parts of the semi-aquatic plants (pH 6, temp. 8ºC).

Indian distribution: East India (Turner 1892); Kodaikanal, (Bharati & Pai 1972);

Vidarbh, Maharashtra (Kamat 1975); Andaman (Prasad & Misra 1985); Uttar

Pradesh (Misra & Srivastava 2003).

This is the first report of the taxon from Eastern Himalaya.

8. Micrasterias tropica Nordstedt

(Krieger 1939, p. 56, pl. 112, f. 3-6; Prescott et al. 1977, p. 193, pl. 140, f. 3, 4)

[Pl. XXX, f. 511, 512]

Cells medium sized, slight longer than broad; sinus opening widely from a sharp-

angled interior; polar lobe with erect, parallel-sided lower part and a diverging

upper part, the apex flat between the long, spreading processes; lateral lobe

undivided, horizontally extended, strongly tapered; with small stout marginal

spines toward the extremities of the lateral lobes and polar processes, and similar

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spines within the margins of all but the extremities; spines stouter or paired at the

depressed apex and above the isthmus; semicells in vertical view fusiform with a

blunt-angled median inflation; marginal and inter-marginal spines present.

Length: 116-119 µm, Breadth: 107-115 µm, Isthmus: 20-22 µm.

Collection No. DD-417, 06.11.2009, Mamencho Lake, Sikkim. In association

with brownish wooly masses growing in water (pH 6, temp. 10ºC).

Indian distribution: East India (Turner 1892); Bandhavgarh (Agarkar & Agarkar

1979), Shimoga district, Karnataka (Hegde 1986a).

This is the first report of the taxon from Eastern Himalaya.

9. Micrasterias zeylanica Fritsch

(Krieger 1937, p. 37, pl. 101, f. 13; Ling & Tyler 1986, p. 33, pl. 21, f. 8-13)

[Pl. XXX, f. 517, 518]

Cells small, slightly longer than broad; sinus open, deep, triangular, acuminate

with a pointed inner termination; semicells 3-lobed, lobes separated by incisions,

which penetrate deeply and are inclined toward the sinus; ends of terminal lobe

bluntly pointed; lateral lobes with two blunt processes, separated by a narrow and

rather shallow, rounded depression, the processes next to the sinus being

horizontal, the other bent down toward the sinus; polar lobe widely spreading,

slightly drawn out at each extremity into a horizontal or deflected process; apex

flatly convex; cell wall smooth.

Length: 62-65 µm, Breadth: 60-62 µm, Isthmus: 10-12 µm.

Collection No. DD-456, 08.11.2009, Kanchanjangha falls, Sikkim. In association

with light greenish-yellow filaments attached on the surface of the wet rock (pH 6,

temp. 14ºC).

Indian distribution: Vidarbh, Maharashtra (Kamat 1975); Andaman (Prasad &

Misra 1985); Shillong, Meghalaya (Gupta 2002); Uttar Pradesh (Misra &

Srivastava 2003); Siddharth Nagar (Prakash et al. 2005); Bihar (Kumar &

Chaudhary 2009); Eastern Himalaya (Yasmin et al. 2011); Kangra, Himachal

Pradesh (Kumar et al. 2012).

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XII. Onychonema Wallich

Cells small, compressed, loosely arranged end to end forming unbranched filament;

median constriction deep, sinus linear, narrow. Semicells mostly elliptic in shape,

sometimes reniform with single stout lateral spine and also 2 capitate apical

processes, nearly as long as the semicells, one process extending over the adjoining

semicell in the front and one in the back. Lateral spines rarely lacking. Cell wall

smooth and colourless. Filaments often embedded in a broad mucilaginous sheath.

Key to the taxa investigated:

1. Apical margin very slightly convex, lateral spines very short

………....(1) O. laeve var. micracanthum

1. Apical margin slightly undulate, lateral spines longer and stout

………………..…(2) O. laeve var. latum

1. Onychonema laeve Nordstedt var. micracanthum Nordstedt

(Croasdale et al. 1983, p. 14, pl. 453, f. 7-9)

[Pl. XXX, f. 519, 520]

Semicells oblong-reniform, 1.3 times broader than long, deeply and narrowly

constricted; sinus linear; the lateral angles ending in a very short spine; apical

processes long and outwardly directed; apices flat; cells loosely joined end to end

forming long pseudo-filament.

Length: 20-23 µm. (with spines), 15-17 µm. (without spines);

Breadth: 22-25 µm. (with spines), 20-23 µm. (without spines);

Isthmus: 6-7 µm.

Collection No. DD-388, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with greenish-brown scum on the surface of the wet rock (pH 6, temp. 10ºC).

Indian distribution: Eastern India (Turner 1892); Vidarbh, Maharashtra (Kamat

1975); Uttar Pradesh (Misra & Srivastava 2003).

This is the first report of the taxon from Eastern Himalaya.

2. Onychonema laeve Nordstedt var. latum West et GS West

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(Croasdale et al. 1983, p. 14, pl. 453, f. 1-6)

[Pl. XXX, f. 521, 522]

Cells compressed, subrectangular, 1.5-2 times broader than long, deeply and

narrowly constricted; the lateral angles ending in a long stout converging spine;

apical processes about as long as the spines; the apex slightly elevated and

truncate, undulate.

Length: 21-23 µm. (with spines), 14-15 µm. (without spines);

Breadth: 33-38 µm. (with spines), 25-29 µm. (without spines);

Isthmus: 5-7 µm.

Collection No. DD-441, 08.11.2009, Pelling, Sikkim. In association with brown

scum on aquatic weeds in a small water body (pH 6, temp. 10ºC).

Indian distribution: Kodaikanal, (Bharati & Pai 1972); Vidarbh, Maharashtra

(Kamat 1975); Kalimpong and Sikkim (Santra & Pal 2006); Kerala (John &

Francis 2010).

XIII. Penium Brébisson ex Ralfs

Cells solitary, cylindrical, straight, elongate or short, median constriction present,

sometimes may be absent. Lateral walls parallel, rarely slight attenuated to truncate or

broadly rounded apex. Girdle bands sometimes evident in some species. Cell wall

smooth but sometimes may be granulate, striated, spinulate or porous and sometimes

may be brown in colour. Chloroplast single, axial, rarely parietal (several spiral

bands) with several longitudinal radiating ridges having one to several pyrenoids in

each semicells. Few species with terminal vacuoles containing granules.

Key to the taxa investigated:

1. Cell wall punctate

2. Punctae very fine, girdle bands absent, margins of the chloroplast serrated

.............(1) P. exiguum var. glaberrimum

2. Punctae relatively prominent, girdle bands present, margins of the chloroplast

entire………………………………............(4) P. margaritaceum var. punctatum

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1. Cell wall striated or granulate

3. Cells elongate, 4-5 times longer than broad, granulate, apex rounded

4. Granules arranged in more or less longitudinal rows

...….(2) P. margaritaceum var. margaritaceum

4. Granule arranged irregularly.................(3) P. margaritaceum var. irregularius

3. Cells stout, less than 2 times longer than broad, apex flat, angles rounded, cell

wall striated……………………….....................................(5) P. phymatosporum

1. Penium exiguum West var. glaberrimum Gronblad

(Krieger 1937, p. 234, pl. 10, f. 11; Prescott et al. 1975, p. 9, pl. 10, f. 13, 14)

[Pl. XXVI, f. 421, 422]

Cells large, cylindrical, 5-5.5 times longer than broad; cells with slight median

constriction; poles truncated with angles rounded and somewhat swollen;

chloroplast with 10 longitudinal, radiating plates which are with serrated margins;

cells smooth.

Length: 116-118 µm, Breadth: 22-23 µm.

Collection No. DD-137, 18.04.2009, Khechiperi Lake, Sikkim. In association

with mass lodged with the submerged leaves of Cryptomeria plants (pH 5.5, temp.

17ºC).

Indian distribution: This is probably the first report of the taxon from India.

2. Penium margaritaceum (Ehrenberg) de Brébisson ex Ralfs var. margaritaceum

(West & GS West 1904, p. 83, pl. 8, f. 32-35; Krieger 1937, p. 230, pl. 10, f. 2-4;

Prescott et al. 1975, p. 9-10, pl. 9, f. 11-13; Lenzenweger 1996, p. 19, pl. 1, f. 9)

[Pl. XXVI, f. 423, 424]

Cells large, long, 3 times longer than broad, cylindrical with rounded apices; wall

brown in colour, rough with granules more or less regularly arranged in vertical

rows; chloroplast two in each semicell, having 8 radiating longitudinal plates.

Length: 79-83 µm, Breadth: 15-19 µm, Apex: 5-7 µm.

Collection No. DD-417, 06.11.2009, Mamencho Lake, Sikkim. In association

with greenish-brown scum on the surface of the wet rock (pH 6, temp. 10ºC). DD-

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717, 01.05.2010, Kalimpong. With phytoplankton sample collected from a small

water body (pH 6.5, temp. 25ºC)

Indian distribution: Eastern India (Turner 1892); Kashmir (Suxena &

Venkateswarlu 1968b); Madhya Pradesh (Agarker & Agarkar 1977); Allahabad

(Pandey & Pandey 1980); Karnataka and Goa (Bharti & Hegde 1982b);

Savandurga, Karnataka (Gurudeva et al. 1983); Kashmir (Compère 1983);

Mamencho Lake, Sikkim (Das & Keshri 2012).

3. Penium margaritaceum (Ehrenberg) Brébisson ex Ralfs var. irregularius West et

GS West

(Krieger 1937, p. 232, pl. 10, f. 5; Prescott et al. 1975, p. 10, pl. 10, f. 1-3)

[Pl. XXVI, f. 425]

Cells medium sized, cells cylindrical with broadly rounded apices, 4-4.5 times

longer than broad; cells slightly constricted at the midregion; cell wall having

irregularly disposed dense granules; chloroplast 2 in each semicell with 4

radiating, longitudinal plates in front view.

Length: 64-71 µm, Breadth: 15-17 µm.

No. DD-382, 06.11.2009, Bitang-cho Lake. Sikkim. In association with green

filamentous mass attached to the surface of the submerged aquatic plants (pH 6,

temp. 10ºC).

Indian distribution: This is probably the first report of the taxon from India.

4. Penium margaritaceum (Ehrenberg) de Brébisson ex Ralfs var. punctatum Ralfs

(Prescott et al. 1975, p. 11, pl. 10, f. 5)

[Pl. XXVI, f. 426, 427]

Cells large, cylindrical, slightly tapering to broadly rounded apices, 7-8 times

longer than broad; cells slightly constricted at the midregion; girdle band is

present in only one semicell here; cell wall punctate, punctae irregularly disposed;

chloroplast single with 6 longitudinal, radiating plates.

Length: 170-173 µm, Breadth: 22-24 µm.

Collection No. DD-201, 19.04.2009, Pharmong falls, Sikkim. In association with

green scum growing in a small rock pool (pH 4.5, temp. 19ºC).

Indian distribution: This is probably the first report of the taxon from India.

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5. Penium phymatosporum Nordstedt

(West & GS West 1904, p. 91, pl. 6, f. 9-11; Krieger 1937, p. 237, pl. 11, f. 14-17;

Prescott et al. 1975, p. 11, pl. 10, f. 20-23; Lenzenweger 1996, p. 19, pl. 1, f. 19)

[Pl. XXVI, f. 428]

Cells short, 1.7-2 times longer than broad, cylindrical with a very slight median

constriction; lateral walls slightly attenuated toward the apices; apex truncated

with rounded angles; chloroplast parietal, single in each semicell; cell wall

striated.

Length: 34-36 µm, Breadth: 19-20 µm.

Collection No. DD-396, 06.11.2009, Babamandir, Sikkim. In association with

mosses under a small stream (pH 6, temp. 8ºC). DD-625, 04.05.2010,

Gurudongmar Lake, Sikkim. In association with brown mass from a rock pool

near the Lake (pH 6, temp. 7ºC).

Indian distribution: This is probably the first report of the taxon from India.

XIV. Pleurotaenium Nageli

Cells solitary, straight, elongate, cylindrical. Median constriction shallow, a notch.

Semicells having basal swelling, usually single, sometimes several basal swellings

can be seen. Lateral walls generally straight, slightly attenuated to the poles or

undulate or with definite nodes. Apex truncate or truncate-rounded, usually smooth,

sometimes with ring of round or conical warts or short spines. Cell wall smooth or

punctate rarely hirsute, sometimes cell wall ornamented with whorls of rectangular

areas. Chloroplast with 2-10 parietal bands parallel or irregularly anastomoising, each

with several pyrenoids.

Key to the taxa investigated:

1. Apex smooth, not furnished with spines

2. Cell wall undulate throughout

3. Cell wall with whorls of rectangular areas...........................(13) Pl. trochiscum

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3. Cell wall with minute pores.....................................................(7) Pl. repandum

2. Cell wall entire, sometimes 1-3 basal undulations present

4. Cell stout, lateral margins strongly convex......(14) Pl. truncatum var. crassum

4. Cells elongate, lateral wall not convex, nearly parallel

5. Cells less than 16 times longer than broad

6. Cell wall smooth...................................(11) Pl. trabecula var. elongatum

6. Cell wall papillate..............................(12) Pl. trabecula var. hutchinsonii

5. Cells more than 16 times longer than broad

7. Cells with 2 prominent basal swellings....(9) Pl. trabecula var. trabecula

7. Cells without any basal swelling..............(10) Pl. trabecula var. crassum

1. Apex with whorls of either circular tubercles or with spines

8. Apex with spines

9. Spines minute, many, arranged in 3 vertical series..................(5) Pl. eugeneum

9. Spines relatively large, 6 in number, arranged in a single series

………………………....(6) Pl. nodosum

8. Apex with tubercles

10. Apical tubercles many, above 10 in face view

……(8) Pl. subcoronulatum f. elongatum

10. Apical tubercles few, below 10 in face view

11. Apical tubercles 3 in face view

12. Cells very much elongate, more than 20 times longer than broad,

lateral walls not abruptly tapered near the apex

……...(4) Pl. ehrenbergii var. elongatum

12. Cell not much elongate, less than 20 times longer than broad, lateral

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walls abruptly tapering near the apex

……..(3) Pl. ehrenbergii var. crenulatum

11. Apical tubercles more than 3 in face view

13. Semicells with 3 well defined basal inflations, pores minute

….....(1) Pl. ehrenbergii var. ehrenbergii

13. Semicells with a single faint basal swelling, pore size relatively big

….............(2) Pl. ehrenbergii var. rectum

1. Pleurotaenium ehrenbergii (Brébisson) de Bary var. ehrenbergii

(West & GS West 1904, p. 205, pl.29, f. 9-11, pl. 30, f. 1; Krieger 1937, p. 410,

pl. 42, f. 4-8; Prescott et al. 1975, p. 114, pl. 45, f. 1-5; Lenzenweger 1996, p. 57,

pl. 7, f. 10, pl. 8, f. 1-2)

[Pl. XXIV, f. 397, 398]

Cells large, 13-15 times longer than broad, slightly constricted; semicells with a

somewhat conspicuous basal inflation and usually with one or two smaller

swelling beyond; margins of the semicells slightly tapered to a rounded-truncate

apex where there are 6 rounded tubercles visible in face view; wall punctate;

chloroplasts in longitudinal, 4 parietal bands in face view, with many pyrenoids.

Length: 621-626 µm, Breadth: 23-30 µm, Apex: 23-25 µm.

Collection No. DD-257, 11.05.2009, Gangtok, Sikkim. In association with wet

mosses growing on the bark of Cryptomeria tree. DD-382, DD-388, 06.11.2009,

Bitang-cho Lake, Sikkim. In association with green filamentous mass attached to

the surface of the submerged aquatic plants (pH 6, temp. 10ºC). DD-631,

04.05.2010, Gurudongmar Lake, Sikkim. With phytoplankton sample collected

from the Lake (pH 6, temp. 9ºC). DD-763, 10.11.11, Lava, West Bengal. In

association with brownish powdery mass from a ditch (pH 6, temp. 18ºC).

Indian distribution: Simla (Kamat 1968b); Kashmir (Suxena & Venkateswarlu

1968b); Gwalior, Madhya Pradesh (Agarkar 1971); Nagpur (Freitas & Kamat

1979); Karnataka and Goa (Bharti & Hegde 1982a); Kodaikanal, (Bharati & Pai

1972); Vidarbh, Maharashtra (Kamat 1975); Uttar Pradesh (Prasad & Mehrotra

1977a); Andamans (Prasad & Misra 1982); Savandurga, Karnataka (Gurudeva et

al. 1983); Karnataka (Bongle 1987); Udalkachar, Madhya Pradesh (Habib 1991);

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West Bengal (Mukherjee & Srivastava 1993); Nagpur, Maharashtra (Tarar et al.

1998); Basti, Uttar Pradesh (Misra et al. 2001); Siddharth Nagar (Prakash et al.

2005); Kalimpong and Sikkim (Santra & Pal 2006); Muriyad, Kerala (Sanilkumar

& Thomas 2006); Southern Himachal Pradesh (Dwivedi et al. 2009); Bihar

(Kumar & Chaudhary 2009); Kodaikanal, Tamilnadu (Singh & Balasingh 2011);

Eastern Himalaya (Yasmin et al. 2011).

This is a fairly common species of Pleurotaenium in India.

2. Pleurotaenium ehrenbergii (Brébisson) de Bary var. ehrenbergii f. rectum

Irénée-Marie

(Prescott et al. 1975, p. 115, pl. 45, f. 6, 7)

[Pl. XXIV, f. 396]

Cells large, 15-17 times longer than broad, slightly constricted with the isthmus

inconspicuous, without a median suture; basal inflation of the semicell slightly

tapered to a truncate apex, where there are 9 rounded tubercles visible; chloroplast

in longitudinal parietal bands with several pyrenoids but not aligned; cell wall

porous.

Length: 603-610 µm, Breadth: 37-40 µm, Apex: 29-33 µm.

Collection No. DD-594, 12.11.2009, Namchi, Sikkim. In association with brown

scum on the surface of the rock under flowing water (pH 6.5, temp. 16ºC).

Indian distribution: This is probably the first report of the taxon from India.

3. Pleurotaenium ehrenbergii (Brébisson) de Bary var. crenulatum (Ehrenberg)

Krieger

(Krieger 1937, p. 413, pl. 43, f. 6; Prescott et al. 1975, p. 116, pl. 45, f. 12, 13)

[Pl. XXIV, f. 400, 401]

Cells large, 16-18 times longer than broad, slightly constricted; semicells with a

somewhat conspicuous basal inflation; margin of the semicell slightly tapered to a

truncately-rounded apex, bearing 5 rounded tubercles visible in the face view; cell

wall porous; chloroplast composed of several longitudinal, parietal bands with

several pyrenoids.

Length: 527-534 µm, Breadth: 30-33 µm, Apex: 16-19 µm.

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Collection No. DD-584, 12.11.2009, Namchi, Sikkim. In association with

greenish scum with wet mosses growing on soil (pH 6.5, temp. 15ºC).

Indian distribution: Amritsar, Punjab (Singh 1966).

This is the first report of the taxon from Eastern Himalaya.

4. Pleurotaenium ehrenbergii (Brébisson) de Bary var. elongatum West

(West & GS West 1904, p. 207, pl. 30, f. 3; Krieger 1937, p. 414, pl. 43, f. 1;

Prescott et al. 1975, p. 117, pl. 46, f. 1-3)

[Pl. XXV, f. 411, 412]

Cells medium sized, very long, 21-26 times longer than broad; semicells straight,

evenly tapered, with a small basal swelling and 3 smaller swellings beyond it;

apex rounded-truncate with 3 rounded tubercles are visible; chloroplast

longitudinal parietal bands with several pyrenoids, cell wall punctate.

Length: 407-412 µm, Breadth: 16-19 µm, Apex: 13-14 µm.

Collection No. DD-18, 16.04.2009, Pelling, Sikkim. In association with light

brown filamentous mass with aquatic weeds from a water body (pH 5, temp.

19ºC).

Indian distribution: Karnataka and Goa (Bharti & Hegde 1982a).

This is the first report of the taxon from Eastern Himalaya.

5. Pleurotaenium eugeneum (Turner) West et GS West

(West & GS West 1904, p. 202; Krieger 1937, p. 417, pl. 44, f. 4, 5; Prescott et al.

1975, p. 118, p. 47, f. 12, 14)

[Pl. XXV, f. 408]

Cells medium sized, 13-15 times longer than broad; semicells with evident basal

inflation and with diminishing undulations beyond it; lateral margins parallel and

very little tapered towards the apex, apex rounded-truncate showing two rows of

small tubercles 10 tubercles each; chloroplast with several scattered pyrenoids;

cell wall smooth.

Length: 554-607 µm, Breadth: 37-45 µm, Apex: 22-25 µm.

Collection No. DD-176, 19.04.2009, Yoksum, Sikkim. In association with brown

filaments growing on a tank (pH 5, temp. 19ºC).

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Indian distribution: Uttar Pradesh (Prasad & Mehrotra 1977); Nagpur (Freitas &

Kamat 1979); Karnataka and Goa (Bharti & Hegde 1982a); Nagpur, Maharashtra

(Tarar et al. 1998)

This is the first report of the taxon from Eastern Himalaya.

6. Pleurotaenium nodosum (Bailey) Lundell var. nodosum

(West & GS West 1904, p. 214, pl. 31, f. 3-6; Krieger 1937, p. 436, pl. 47, f. 1;

Prescott et al. 1975, p. 125, p. 44, f. 1-3; Lenzenweger 1996, p. 59, pl. 8, f. 3)

[Pl. XXV, f. 416, 417]

Cells large crenate in face view, 5-6 times longer than broad; semicells with

nodulose margins caused by 4 evenly spaced rings of prominent nodules, 5-9 in

each ring; semicells tapering very slightly to the apex which is slightly dilated,

rounder-truncate, and furnished with a crown of 6 conical teeth which do not

project beyond the extreme apex; wall smooth; chloroplast consisting of parietal

bands.

Length: 276-278 µm, Breadth: 46-50 µm, Apex: 28-29 µm.

Collection No. DD-391, 06.11.2009, Bitang cho Lake, Sikkim. In association

with brownish scum attached to the submerged part of the semi-aquatic plants (pH

6 temp 10ºC).

Indian distribution: Eastern India (Turner 1892).

This is the first report of the taxon from Eastern Himalaya.

7. Pleurotaenium repandum (Wolle) Krieger var. repandum f. repandum

(Krieger 1937, p. 405, pl. 41, f. 9; Prescott et al. 1975, p. 129, pl. 41, f. 10)

[Pl. XXIV, f. 405, 406]

Cells medium sized, 14-17 times longer than broad; semicells very slightly

tapered from base to apex, basal inflation very slight, the entire margins undulate;

apex truncate, wall finely punctate.

Length: 247-252 µm, Breadth: 15-18 µm, Apex: 11-12 µm.

Collection No. DD-584, 12.11.2009, Namchi, Sikkim. In association with

greenish scum with wet mosses growing on soil (pH 6.5, temp. 15ºC).

Indian distribution: This is probably the first report of the taxon from India.

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8. Pleurotaenium subcoronulatum (Turner) West & West var. subcoronulatum f.

elongatum Croasdale et Scott

(Prescott et al. 1975, p. 132, pl. 49, f. 5)

[Pl. XXIV, f. 399]

Cells large, 24-32 times longer than broad; semicells with slight basal swelling;

slightly undulate to the apex forming little bulbous-swollen tip, on which 12

rounded tubercles are visible in face view; both margins nearly parallel to each

other; entire wall covered with minute erect spines except the apex.

Length: 737-743 µm, Breadth: 38-42 µm, Apex: 44-45 µm.

Collection No. DD-391, 06.11.2009, Bitang cho Lake, Sikkim. In association

with brownish scum attached to the submerged part of the semi-aquatic plants (pH

6 temp 10ºC).

Indian distribution: This is probably the first report of the taxon from India.

9. Pleurotaenium trabecula (Ehrenberg) Nageli var. trabecula

(West & GS West 1904, p. 209, pl. 30, f. 11-13; Krieger 1937, p. 395, pl. 40, f. 1-

4; Prescott et al. 1975, p. 133, pl. 40, f. 1-5; Lenzenweger 1996, p. 59, pl. 7, f. 4)

[Pl. XXIV, f. 404; pl. XXV, f. 409, 410]

Cells large, 10-17 times longer than broad; basal inflation slight but definite, with

1-2 swelling beyond it; lateral margins straight and parallel or little swollen in the

midregion and very slightly tapered toward the apex which is truncate with

rounded angles; cell wall finely punctate, punctae irregular.

Length: 425-528 µm, Breadth: 25-50 µm, Apex: 17-31 µm.

Collection No. DD-412, 06.11.2009, Mamencho Lake, Sikkim. In association

with dark greenish filament floating freely on the surface of water (pH 6, temp.

10ºC). DD-501, Changey falls, Sikkim. In association with filamentous mass

growing on the rock under the water (pH 6, temp. 14ºC). DD-717, 01.05.2010,

Kalimpong. With phytoplankton sample collected from a small waterbody (pH

6.5, temp. 25ºC).

Indian distribution: Eastern India (Turner 1892); Kodaikanal, Tamilnadu

(Iyengar & Vimla Bai 1941; Singh & Balasingh 2011); Andhra Pradesh (Suxena

& Venkateswarlu 1968a); Gwalior, Madhya Pradesh (Agarkar 1969); Vidarbh,

Maharashtra (Kamat 1975); Uttar Pradesh (Prasad & Mehrotra 1977); Nagpur

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(Freitas & Kamat 1979); Allahabad (Pandey & Pandey 1980); Karnataka and Goa

(Bharti & Hegde 1982a); Savandurga, Karnataka (Gurudeva et al. 1983);

Udalkachar, Madhya Pradesh (Habib 1991); Uttarakhand (Misra et al. 2007);

Uttar Pradesh (Shukla et al. 2008); Southern Himachal Pradesh (Dwivedi et al.

2009); Eastern Himalaya (Yasmin et al. 2011).

10. Pleurotaenium trabecula (Ehrenberg) Nageli var. crassum Wittrock

(Krieger 1937, p. 399, pl. 40, f. 6; Prescott et al. 1975, p. 134, pl. 40, f. 13, 14;

Lenzenweger 1996, p. 60, pl. 7, f. 5)

[Pl. XXV, f. 418]

Cells medium sized, stout, 4-6 times longer than broad; lateral walls slightly

convex forming truncate apex with rounded angles; cell wall slightly tapered

toward the apex; cell wall smooth.

Length: 224-231 µm, Breadth: 40-55 µm, Apex: 20-26 µm.

Collection No. DD-379, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with deep green filamentous mass floating freely on the surface of water forming

bloom (pH 6, temp. 10ºC).

Indian distribution: This is probably the first report of the taxon from India.

11. Pleurotaenium trabecula (Ehrenberg) Nageli var. elongatum Cedergren

(Krieger 1937, p. 399, pl. 40, f. 5; Prescott et al. 1975, p. 134, p. 40, f. 10-11)

[Pl. XXV, f. 407]

Cells medium sized, 18-20 times longer than broad; basal inflation slight but

definite; lateral margin parallel but very slight broad at the apex forming truncate

apex with rounded angles; chloroplast parietal with scattered pyrenoids; cell wall

finely punctate.

Length: 734-745 µm, Breadth: 38-39 µm. Apex: 41-44 µm.

Collection No. DD-223, Changu Lake, Sikkim. With water sample collected from

the Lake (pH 6, temp. 6ºC). DD-792, 11.11.2011, Rishop, West Bengal. In

association with reddish yellow powdery mass with the mosses growing in a drain

(pH 6, temp. 20ºC). DD-756, 10.11.2011, Lava, West Bengal. In association with

green filaments floats freely on the surface of a small water body (pH 6, temp

17ºC).

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Indian distribution: Nagpur (Freitas & Kamat 1979); Nagpur, Maharashtra

(Tarar et al. 1998).

This is the first report of the taxon from Eastern Himalaya.

12. Pleurotaenium trabecula (Ehrenberg) Nageli var . hutchinsonii (Turner)

Croasdale

(Prescott et al. 1975, p. 135, p. 40, f. 6)

[Pl. XXV, f. 413]

Cells long, slender, 16-18 times longer than broad; basal inflations definite with 3

swellings; lateral walls parallel forming truncate apex with rounded angles; cell

wall entirely covered with small dense papillae; chloroplast with 3 longitudinal

bands.

Length: 457-465 µm, Breadth: 26-28 µm. Apex: 13-15 µm.

Present specimen tallies with the type but differs in,

1. Much larger

2. 3 basal swellings.

Collection No. DD-417, 06.11.2009, Mamencho Lake, Sikkim. In association

with greenish-brown scum on the surface of the wet rock (pH 6, temp. 10ºC).

Indian distribution: This is probably the first report of the taxon from India.

13. Pleurotaenium trochiscum West et GS West

(Krieger 1937, p. 437, pl. 51, f. 2; Prescott et al. 1975, p. 136, pl. 50, f. 9-12)

[Pl. XXV, f. 414, 415]

Cells medium sized, 8-10 times longer than broad; semicells cylindrical with

straight margins, very slightly tapered to the smooth, truncate- rounded apex; cell

wall with 15 circles of rectangular thinner areas each circles having 4-5 areas,

areas rectangular with rounded angles; apex having few granules; chloroplast

having 6 longitudinal ridges with scattered pyrenoids; cell wall smooth.

Length: 244-248 µm, Breadth: 25-28 µm, Apex: 15-16 µm.

Collection No. DD-381, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with brownish scum attached to the surface of the submerged parts of the semi-

aquatic plants (pH 6, temp. 10ºC).

Indian distribution: This is probably the first report of the taxon from India.

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14. Pleurotaenium truncatum (Brébisson) Nageli var. crassum Boldt f. crassum

(West & GS West 1904, p. 204; Krieger 1937, p. 432, pl. 49, f. 7; Prescott et al.

1975, p. 137, pl. 46, f. 9-11; Lenzenweger 1996, p. 60, pl. 8, f. 5)

[Pl. XXIV, f. 402, 403]

Cells large, stout, 2-3 times longer than broad; semicells swollen beyond the basal

inflation, margins strongly convex and tapering to the apex; apex truncate with

rounded angles, apical tubercles absent; wall smooth, whitish-yellow in colour.

Length: 225-228 µm, Breadth: 75-82 µm, Isthmus: 44-47 µm, Apex: 25-26 µm.

Collection No. DD-585, 12.11.2009, Namchi, Sikkim. With phytoplankton

collected from a small waterfalls (pH 6.5, temp. 15ºC).

Indian distribution: This is probably the first report of the taxon from India.

XV. Spondylosium Brébisson ex Kutzing

Cells small to medium sized, compressed, flattened, often deeply constricted with a

narrow or open sinus; semicells in vertical view elliptic, triangular or lobed, bi-radiate

or tri-radiate in end view; cells united by end to end into filaments by remains of

primary wall between closely appresses secondary wall at apices which is flat or

slightly retuse; filaments sometimes sheathed with thick gelatinous stalk. Cell wall

generally smooth, sometimes with pores scattered or arranged in series, rarely with

papillose on the lateral walls. Chloroplast axial, single, with a central or several

pyrenoids in each semicells.

Key to the taxa investigated:

1. Apex broad and flat, in vertical view cell bi-radiate…………………(2) Sp. planum

1. Apex elevated, evenly convex, in vertical view cells tri-radiate

…………..(1) Sp. nitens var. triangulare

1. Spondylosium nitens (Wallich) Archer var. triangulare Turner

(Croasdale et al. 1983, p. 21, pl. 458, f. 4, 5)

[Pl. XXVI, f. 435, 436]

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Cells small, slightly broader than long, loosely arranged end to end forming

pseudo-filament; semicells 3-lobed, the sinus open and broadly rounded within;

some portion of the apex elevated and flattened; semicells in face view dumbbell-

shaped.

Length: 16-19 µm, Breadth: 19-22 µm, Isthmus: 14-16 µm.

Collection No. DD-585, 12.11.2009, Namchi, Sikkim. With phytoplankton

sample collected from a small waterfall (pH 6.5, temp. 15ºC).

Indian distribution: Eastern India (Turner 1892); Kashmir (Compère 1983).

This is the first report of the taxon from Eastern Himalaya.

2. Spondylosium planum (Wolle) West et GS West var. planum

(West et al. 1923, p. 222, pl. 155, f. 23-25; Croasdale et al. 1983, p. 21, pl. 456, f.

6, 6a, 7; Lenzenweger 1997, p. 144, pl. 43, f. 16)

[Pl. XXVI, f. 437]

Cells of medium size, slightly broader than long, sub-cylindrical with rounded

angles, deeply constricted, sinus obtuse and open; apex flat with angles rounded;

cell wall smooth; chloroplast parietal with few pyrenoids.

Length: 13-19 µm, Breadth: 16-20 µm, Isthmus: 6-7 µm.

Collection No. DD-396, 06.11.2009, Babamandir, Sikkim. In association with

mosses under a rock pool (pH 6, temp. 8ºC). DD-361, 05.11.2009, Banjakhri falls,

Sikkim. In association with black scum on soil and rocks under running water (pH

6, temp. 15ºC).

Indian distribution: Ranchi, Bihar (Sinha & Mishra 1967); Kodaikanal, (Bharati

& Pai 1972); Vidarbh, Maharashtra (Kamat 1975); Savandurga, Karnataka

(Gurudeva 1983); Rohilkhand, Uttar Pradesh (Habib 1993); Pilibhit, Uttar Pradesh

(Habib 1997); Goalpara, Assam (Deca et al. 2011).

XVI. Sturastrum Meyen ex Ralfs

Cells solitary, small to large, with usually deep sometimes shallow median

constriction, sinus wide open, rarely closed. In end view cell 2-12 radiate, processes

may be long or short usually with 2 or several short terminal spinules and several

verticals series of granules, denticles, spines or verrucae. Semicells semicircular,

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elliptic, oblong elliptical, pyramidal or oval, apex convex, smooth or crenate or with

ring of granules, sometimes angles of the semicells rounded, truncate or with short

processes. Cell wall smooth or variously ornamented with granules, spines or

verrucae. Chloroplast axial, stellate single in each semicell with one to several

pyrenoids.

Key to the taxa investigated:

1. Angles of the semicells not produced to form arms or elongated processes

2. Cell wall smooth, without granules, verrucae, pores or punctae..............

..........(7)St. habeebense

2. Cells ornamented with granules, verrucae, pores or punctae

3. Cell wall punctate or porous

4. Semicells transversely elliptic

5. Sinus acute at the apex, opening outwardly, cell wall porous, pores large

…………..………..…..(1) St. bieneanum

5. Sinus broadly ‘U’ shaped, cell wall densely, punctae minute

………...(2) St. bineanum var. ellipticum

4. Semicells shaped otherwise

6. Semicells semicircular

7. Sinus narrow, open outwardly…….(14) St. orbiculare var. orbiculare

7. Sinus closed entirely………………..….(15) St. orbiculare var. minor

6. Semicells sub-reniform……………...………...(13) St. muticum f. minus

3. Cell wall with granules or verrucae

8. Semicells elliptical, dorsal margins somewhat more convex than the

vertical, apex broadly rounded.…..(16) St. punctulatum var. subproductum

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8. Semicells elongate elliptical, ventral margin convex, apex nearly flat

………………………(8) St. lapponicum

1. Angles of the semicells either apically or laterally produced to form arms or

processes or spines

9. Angles with spines

10. Spines minute, very small

11. Semicells obversely triangular, angles with a single small spine

……..………(5) St. dejectum var. patens

11. Semicells transversely rectangular, angles with two spines

12. Sinus broad, basal margins slightly concave…………..(4) St botanense

12. Sinus acute at the apex, basal margins slightly convex......(6) St. duplex

10. Spines larger and longer

13. Spines single………...………………………..………...(11) St. mamillatum

13. Spines bifid……………………………...……..…………..…(3) St. bifidum

9. Angles with arms, blunt or having rings of granules or with short spines

14. Processes with concentric rings of granules

15. Processes directed upward……………..…………….(20) St. tetracerum

15. Processes laterally directed

16. Semicells with apical rings of granules like a crown

17. Cell 6-radiate, processes ends with several small granules or

spines……………………………..……….(19) St. talisheekense

17. Cell 4-radiate, processes with blunt ends

.….(18) St. striolatum var. striolatum f. brasiliense

16. Apex of the semicells smooth………..……..(12) St. margaritaceum

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14. Processes without concentric rings of granules, either smooth or

ornamented otherwise

18. Semicells broadly cyathiform, apex broadly convex, processes

downwardly……………………………………….(17) St. sonthalium

18. Semicells broadly bowl-shaped, apex flat, processes laterally directed

19. Apex with low verrucae……..….………...…(9) St. longibrachiatum

19. Apex with series of small granules extended end to end to the

processes…………………….(10) St. longibrachiatum var. inflatum

1. Staurastrum bieneanum Rabenhorst var. bieneanum

(West & GS West 1912, p. 135, pl. 120, f. 4-6; Prescott et al. 1982, p. 141, pl.

333, f. 7-9; Lenzenweger 1997, p. 74, pl. 24, f. 3-5)

[Pl. VII, f. 222; pl, VIII, f. 255, 256]

Cells medium sized, slightly broader than long; median constriction deep, the

sinus acute at the apex, opening outwardly; semicells transversely elliptic, the

base symmetrically convex to the apical angles which are sharply rounded; the

apical margin convex; cell wall punctate.

Length: 26-29 µm, Breadth: 29-30 µm, Isthmus: 5-7 µm.

Collection No. DD-583, 12.11.2009, Namchi, Sikkim. In association with

greenish-brown scum with mosses in a small rock pool (pH 6.5, temp. 14ºC). DD-

717, 01.05.2010, Kalimpong. With phytoplankton sample collected from a small

water body (pH 6.5, temp. 25ºC).

Indian distribution: Andhra Pradesh (Suxena & Venkateswarlu 1966a); Uttar

Pradesh (Prasad & Mehrotra 1977b); Rohilkhand, Uttar Pradesh (Habib 1993);

Hardoi, Uttar Pradesh (Habib 2009).

This is the first report of the taxon from Eastern Himalaya.

2. Staurastrum bieneanum Rabenhorst var. ellipticum Wille

(West & GS West 1912, p. 137, pl. 120, f. 7; Prescott et al. 1982, p. 142, pl. 333,

f. 5, 6)

[Pl. VIII, f. 259, 260]

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Cells medium sized, slightly longer than broad; median constriction deep, sinus

open, U-shaped, extremity rounded; semicells transversely elliptical with apical

margin convex, angles rounded; in vertical view cells triangular, margins slightly

retuse, angles broadly rounded; cell wall minutely punctate.

Length: 36-38 µm, Breadth: 33-36 µm, Isthmus: 16-17 µm.

Collection No. DD-414, 06.11.2009, Mamencho Lake, Sikkim. In association

with green filamentous mass attached to the surface of the submerged aquatic

plants (pH 6, temp. 10ºC).

Indian distribution: Uttar Pradesh (Misra & Srivastava 2003).

This is the first report of the taxon from Eastern Himalaya.

3. Staurastrum bifidum (Ehrenberg) Brébisson

(West et al. 1923, p. 32, pl. 134, f. 4; Prescott et al. 1982, p. 142, pl. 363, f. 13;

Lenzenweger 1997, p. 75, pl. 29, f. 10)

[Pl. VIII, f. 244, 245]

Cells medium sized, 1.5-2 times broader than long; median constriction slight, the

sinus obtuse at the apex, widely open; semicells semi-elliptical, the basal margins

symmetrically convex to acutely rounded apical angles which bear a pair of long

sharp, superimposed spines, the apical margin broadly convex; cell wall smooth;

in vertical view cells triangular, the margins concave, the poles bifurcate and

furnished with 2 stout spines in a slightly different plane.

Length: 30-32 µm, Breadth: 52-57 µm. (with spine), Breadth: 33-39 µm. (without

spine), Isthmus: 13-15 µm.

Collection No. DD-379, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with deep green filamentous mass floating freely on the surface of water bloom

(pH 6, temp. 10ºC). DD-805, 11.11.2011, Rishop, West Bengal. In association

with reddish-green with mosses on the bark.

Indian distribution: Eastern India (Turner 1892); Kodaikanal, (Bharati & Pai

1972); Savandurga, Karnataka (Gurudeva et al. 1983); Quilon, Kerala (Sindhu &

Panikkar 1995b).

This is the first report of the taxon from Eastern Himalaya.

4. Staurastrum botanense Playfair var. botanense

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(Prescott et al. 1982, p. 144, pl. 363, f. 6-8)

[Pl. VII, f. 226-228]

Cells small, 1-1.5 times longer than broad; median constriction deep, the sinus

acutely rounded at the apex, widely open; semicells obversely triangular, with the

apical lobes produced and bearing two superimposed spines, the lower bifid, the

basal margin convex and diverging, the apical margin truncate and straight; in

vertical view cells triangular, the margins slightly concave; the poles rounded and

bearing 2 superimposed spines.

Length: 21-22 µm (with spine), Length: 16-18 µm (without spine), Breadth: 17-18

µm (with spine), Breadth: 14-15 µm (without spine), Isthmus: 7-8 µm.

Collection No. DD-583, 12.11.2009, Namchi, Sikkim. In association with

greenish-brown scum with mosses on a small rock pool (pH 6.5, temp. 14ºC).

DD-792, 11.11.2011, Rishop, West Bengal. In association with reddish yellow

powdery mass with the mosses growing in a drain (pH 6, temp. 20ºC).

Indian distribution: This is probably the first report of the taxon from India.

5. Staurastrum dejectum (Brébisson) Ralfs var. patens Nordstedt

(West et al. 1923, p. 9, pl. 130, f. 1, 2; Prescott et al. 1982, p. 181, pl. 350, f. 8, 9,

11, 12; pl. 255, f. 11)

[Pl. VII, f. 236-238]

Cells medium sized, about as long as broad; median constriction deep, sinus acute

angled, opened; semicells obversely triangular, bowl shaped; the lateral margins

convex; the apical angles which are narrowly rounded and furnished with a very

short, diverging spine; apical margin straight; cell wall smooth; in vertical view

cells triangular, margin slightly convex, the angles tumid, narrowly rounded and

bearing a stout spine.

Length: 21-22 µm, Breadth: 23-25 µm, Isthmus: 6-8 µm.

Collection No. DD-389, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with brownish scum attached to the submerged part of the semi-aquatic plants (pH

6, temp. 10ºC). DD-716, 01.05.2010, Kalimpong. In association with blue green

filaments attached on the submerged aquatic plant under a small water body (pH

6.5, temp. 25ºC).

Indian distribution: Karnataka (Hegde 1987).

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This is the first report of the taxon from Eastern Himalaya.

6. Staurastrum duplex Wolle

(Prescott et al. 1982, p. 192, pl. 381, f. 8)

[Pl. VIII, f. 241-243]

Cells small, 1.3-1.5 times longer than broad; median constriction moderately deep,

the isthmus rather broad, the sinus acute at the apex, open; semicells transversely

rectangular, the vertical margin convex and then concave into lower, basal

processes which are bi-spinate, the lateral margins vertical and parallel to the

upper angles which are similarly extended into short, truncate, bi-spinate

processes, the apical margin broadly convex; cell wall smooth; in vertical view

cells triangular, the margins broadly concave, the angles extended into bifurcate

processes which are bi-spinate.

Length: 27-29 µm, Breadth: 19-21 µm, Isthmus: 3-4 µm, Thickness: 16-18 µm.

Collection No. DD-380, 06.11.2009 Bitang-cho Lake, Sikkim. In association with

green scum in a swamp (pH 6, temp. 10ºC).

Indian distribution: This is probably the first report of the taxon from India.

7. Staurastrum habeebense Irénée-Marie

(Prescott et al. 1982, p. 218, pl. 328, f. 8)

[Pl. VII, f. 239, 240]

Cells medium sized, 1.5-1.6 times longer than broad; semicells with a shallow

median constriction, the sinus broadly open, the isthmus broad; semicells

pentagonal, the lower margins diverging to broadly rounded lateral angles, then

converging and somewhat concave to the rounded apical angles; the apical margin

truncate-retuse; cell wall finely punctate; chloroplast axial, with single pyrenoid in

each semicell.

Length: 44-45 µm, Breadth: 28-29 µm, Isthmus: 13-15 µm.

Collection No. DD-414, 06.11.2009, Mamencho Lake, Sikkim. In association

with green filamentous mass attached to the surface of the submerged aquatic

plants (pH 6, temp. 10ºC).

Indian distribution: Karnataka (Hegde 1987).

This is the first report of the taxon from Eastern Himalaya.

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8. Staurastrum lapponicum (Schmidle) Gronblad

(Prescott et al. 1982, p. 231, pl. 337, f. 1, 3; Lenzenweger 1997, p. 100, pl. 25, f.

7)

[Pl. VIII, f. 249, 250]

Cells small, slightly broader than long, median constriction deep, sinus acute at

the apex, then diverging; semicells transversely elongate-elliptic; apex broadly

convex; lateral angles acutely rounded; in vertical view cells triangular, margins

concave, angles rounded; cell wall granular entire margin.

Length: 23-24 µm, Breadth: 26-27 µm, Isthmus: 10-11 µm.

Our specimen is close to the type species but is smaller in all respects.

Collection No. DD-17, 16.04.2009, Pelling, Sikkim. In association with slimy

filaments on the margin of a small Lake (pH 5, temp. 19ºC).

Indian distribution: This is probably the first report of the taxon from India.

9. Staurastrum longibrachiatum (Borge) Gutwinski

(Prescott et al. 1982, p. 240, pl. 415, f. 6)

[Pl. VII, f. 229, 230]

Cells medium sized with processes, about twice as broad as long with processes;

median constriction slight, the sinus a broad notch, obtusely rounded at the apex;

semicells broadly bowl-shaped, basal angles at the opening of the sinus furnished

with a bi-spinate protrusion, the margins diverging into the apical processes which

have 2 bi-spinate protrusions at the base, these becoming a series of teeth on the

ventral margin of the process, thus giving the margins of the semicell a series of

incisions and verrucae, the apical angles extended into long, slender processes,

horizontally directed, bispinate at the tip; the apical margins truncate, straight and

slightly depressed between the processes, furnished with a marginal series of

verrucae.

Length: 32-33 µm, Breadth: 59-62 µm, Isthmus: 9-11 µm.

Collection No. DD-583, 12.11.2009, Namchi, Sikkim. In association with

greenish-brown scum with mosses in a small rock pool (pH 6.5, temp. 14ºC).

Indian distribution: Karnataka (Hegde 1987).

This is the first report of the taxon from Eastern Himalaya.

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10. Staurastrum longibrachiatum (Borge) Gutwinski var. inflatum Scott et Prescott

(Prescott et al. 1982, p. 240, pl. 415, f. 10)

[Pl. VIII, f. 265, 266]

Cells medium sized with long processes, 1.5-2 times broader than long; median

constriction shallow, sinus broad; semicells broadly bowl shaped; apical angles

extended into long processes, horizontally directed, processes tipped with 3 small

spines and furnished with double series of granules extended to the apex, margins

of the processes with faint undulations; another series of granules at the lateral

margins extending to the sinus on either side; apical margins truncate, slightly

convex at the middle, furnished with a marginal series of granules like a crown;

cell wall punctate.

Length: 32-33 µm, Breadth: 53-56 µm (with processes), 21-23 µm (without

processes), Isthmus: 5-7 µm.

Collection No. DD-24, 16.04.2009, Pelling, Sikkim. In association with dark

green to brownish blue mat in a small drain (pH 5.5, temp. 21ºC).

Indian distribution: Karnataka (Hegde 1987).

This is the first report of the taxon from Eastern Himalaya.

11. Staurastrum mamillatum Nordstedt

(Prescott et al. 1982, p. 246, pl. 349, f. 9, 11)

[Pl. VIII, f. 257, 258]

Cells small, 1.3-1.5 times longer than broad; median constriction a broad

invagination, the sinus a notch, the isthmus narrow and elongated; semicells

obversely triangular, the basal margins slightly convex and diverging directly to

the apical angles which are capitate-inflated and bear a slender, slightly curved,

downward projected spine; apical margin convex and somewhat elevated in the

mid sector; cell wall smooth; in vertical view cell triangular, the margins concave

between the inflated lobes which bear a curved spines at the apex.

Length: 30-32 µm, Breadth: 39-42 µm (with spine), Breadth: 25-27 µm (without

spine), Isthmus: 6-7 µm.

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Collection No. DD-379, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with deep green filamentous mass floating freely on the surface of water bloom

(pH 6, temp. 10ºC).

Indian distribution: This is probably the first report of the taxon from India.

12. Staurastrum margaritaceum (Ehrenberg) Ralfs

(West et al. 1923, p. 131, pl. 150, f. 5-9; Prescott et al. 1982, p. 248, pl. 390, f. 1,

3; pl. 391, f. 1, 2; Lenzenweger 1997, p. 103, pl. 31, f. 1-5)

[Pl. VIII, f. 261, 262]

Cells small, slightly longer than broad; median constriction shallow, the sinus an

open notch at the apex of a broad invagination; semicells cup-shaped, the basal

margins slightly convex and diverging to stout, truncate lateral projections at the

apex which mostly are horizontally directed; the apical margin convex; face of the

semicells with vertical series of granules encircling the arms and with a transverse

series of supra-isthmial granules; in vertical view cell 5-rayed, the margins deeply

concave between broadly rounded lobes with transverse series of granules over

the lobes and on the body of the cell except the midregion.

Length: 26-28 µm, Breadth: 29-30 µm, Isthmus: 8-9 µm.

Collection No. DD-389, 06.11.2009 Bitang-cho Lake, Sikkim. In association with

light green filaments on the surface of the water (pH 6, temp. 10ºC).

Indian distribution: Eastern India (Turner 1892); Madhya Pradesh (Agarkar &

Agarkar 1979); Gujarat (Kumar & Patel 1990b).

This is the first report of the taxon from Eastern Himalaya.

13. Staurastrum muticum (Brébisson) Ralfs var. muticum f. minus Rabenhorst

(West & GS West 1912, p. 133, pl. 118, f. 16-20; Prescott et al. 1982, p. 257, pl.

332, f. 1-3, 5)

[Pl. VII, f. 223-225]

Cells medium sized, very slightly longer than broad; semicells narrowly elliptic-

oval, wide; the dorsal margins less convex than the ventral; medium constriction

deep, the sinus obtusely rounded at the apex, linear but open; in vertical view cells

triangular, narrowly rounded at the angles, the margins retuse between the lobes;

cell wall finely and densely punctate.

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Length: 21-22 µm, Breadth: 19-21 µm, Isthmus: 7-8 µm.

Collection No. DD-584, 12.11.2009, Namchi, Sikkim. In association with

greenish scum with wet mosses growing on soil (pH 6.5, temp. 15ºC).

Indian distribution: This is probably the first report of the taxon from India.

14. Staurastrum orbiculare (Ehrenberg) Ralfs

(Prescott et al. 1982, p. 268, pl. 330, f. 3; pl. 331, f. 15, 16)

[Pl. VIII, f. 253, 254]

Cells medium sized, very slightly broader than long; median constriction deep, the

sinus slightly dilated at the apex, linear, closed; basal angles rounded; cell wall

punctate; in vertical view cell triangular, the margins concave between broadly

rounded lobes.

Length: 16-17 µm, Breadth: 17-18 µm, Isthmus: 6-7 µm.

This form is very close to S. muticum (Brébisson) Ralfs since the sinus is linear

and acute angled, the taxon has been placed under S. orbiculare. However our

plant is smaller than the typical and the existing varieties of St. orbiculare.

Collection No. DD-379, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with deep green filamentous mass floating freely on the surface of water forming

bloom (pH 6, temp. 10ºC).

Indian distribution: Eastern India (Turner 1892); Vidarbh, Maharashtra (Kamat

1975); Nagpur (Freitas & Kamat 1979); Gujarat (Kumar & Patel 1990b).

This is the first report of the taxon from Eastern Himalaya.

15. Staurastrum orbiculare (Ehrenberg) Ralfs var. minor Prescott

(Prescott et al. 1982, p. 269, pl. 331, f. 8)

[Pl. VII, f. 233-235]

Cells small, very slightly broader than long, almost circular in general outline;

median constriction deep, the sinus slightly dilated at the apex, linear, closed;

semicells sub-semicircular, the apex slightly depressed but broadly rounded; basal

angles rounded; cell wall punctate; in vertical view cell triangular, the margins

concave between broadly rounded lobes.

Length: 20-22 µm, Breadth: 22-25 µm, Isthmus: 10-11 µm.

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Collection No. DD-585, 12.11.2009, Namchi, Sikkim. With phytoplankton

sample collected from a small waterfall (pH 6.5, temp. 15ºC).

Indian distribution: Kashmir (Compère 1983).

This is the first report of the taxon from Eastern Himalaya.

16. Staurastrum punculatum (Brébisson) Ralfs var. subproductum West et GS West

(West & GS West 1912, p. 182, pl. 127, f. 15; Prescott et al. 1982, p. 294, pl. 339,

f. 8)

[Pl. VIII, f. 251, 252]

Cells small, very slightly longer than broad, cuneiform; median constriction deep,

the sinus acute at the apex, open; semicells elliptical, the dorsal margins somewhat

more convex than the ventral, the ventral margins diverging directly into the

apical angles which are slightly produced and narrowly rounded; the apical

margins concave, slightly elevated in the midsector; cell wall with concentric

series of granules over the lobes; cells in vertical view triangular, the margins

slightly convex, the lobes narrowly rounded and produced with concentric series

of granules.

Length: 30-33 µm, Breadth: 29-32 µm, Isthmus: 13-15 µm.

Collection No. DD-191, 19.04.2009, Yoksum, Sikkim. In association with

greenish scum in stagnant water under a small falls (pH 5.5, temp. 18ºC)

Indian distribution: This is probably the first report of the taxon from India.

17. Staurastrum sonthalianum Turner

(Turner 1892, p. 124, t. 14, f. 27; Prescott et al. 1982, p. 314, pl. 442, f. 1)

[Pl. VII, f. 231, 232]

Cells large, 1.5-1.6 times broader than long; median constriction deep, the sinus

open; semicells broadly cyathiform, the vertical margin concave and then

diverging into the apical angles which are produced to form very long, tapering

and downwardly directed spines, the processes of the 2 semicells nearly in contact

at their apices, the apical and dorsal margins, including the apical margin

decorated with a continuous series of low verrucae, the processes tipped with 2

teeth; wall smooth.

Length: 32-34 µm, Breadth: 51-52 µm, Isthmus: 6-8 µm.

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Collection No. DD-382, 06.11.2009 Bitang-cho Lake, Sikkim. In association with

green filamentous mass attached to the surface of the submerged aquatic plants

(pH 6, temp. 10ºC).

Indian distribution: Eastern India (Turner 1892); Kodaikanal, Tamilnadu (Singh

& Balasingh 2011); Kolhapur, Maharashtra (Leela et al. 2012).

This is the first report of the taxon from Eastern Himalaya.

18. Staurastrum striolatum (Nageli) Archer var. striolatum f. brasiliense Turner

(Prescott et al. 1982, p. 318, pl. 338, f. 16, 18)

[Pl. VII, f. 219-221]

Cells small, about as long as broad; median constriction shallow, sinus open U-

shaped, semicells narrowly sub-elliptic; in vertical view cells 4-radiate, margins

deeply convex between the processes, processes short with blunt endings with

rounded angles; processes horizontally placed and furnished with 3 vertical series

of granules; apical margins truncate; face of the semicells with scattered granules;

cell wall smooth.

Length: 22-23 µm, Breadth: 23-26 µm, Isthmus: 4-5 µm.

Collection No. DD-583, 12.11.2009, Namchi, Sikkim. In association with

greenish-brown scum with mosses in a small rock pool (pH 6.5, temp. 14ºC).

Indian distribution: Eastern India (Turner 1892).

This is the first report of the taxon from Eastern Himalaya.

19. Staurastrum talisheekense Scott et Gronblad

(Prescott et al. 1982, p. 329, pl. 441, f. 2)

[Pl. VIII, f. 246-248]

Cells medium sized, about as long as broad; median constriction shallow, sinus

broad with slight notch, semicells cyathiform, broadly bowl shaped, basal margins

inflated; end view cells 6-radiate, processes short, slightly attenuated to truncate

extremities having small 5-5 spines at the tips, margins deeply concave between

processes; lateral processes furnished with 3 vertical rows of granules; apical

margins broadly convex, with a circular ring of small spines leaving median

portion smooth; cell wall smooth.

Length: 41-44 µm, Breadth: 41-45 µm, Isthmus: 15-16 µm.

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Collection No. DD-389, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with light green filaments on the surface of the water (pH 6, temp. 10ºC).

Indian distribution: This is probably the first report of the taxon from India.

20. Staurastrum tetracerum (Kutzing) Ralfs var. tetracerum

(West et al. 1923, p. 118, pl. 149, f. 2, 3; Prescott et al. 1982, p. 331, pl. 402, f. 5,

7, 9)

[Pl. VIII, f. 263, 264]

Cells very small, as broad as long including the processes; median constriction

deep, forming a V-shaped invagination, the sinus with a sub-acute apex; semicells

conversely triangular, the lower margins diverging directly from the sinus into the

apical angles which are extended to form upward diverging processes, the margins

serrulate but apparently without teeth at the apices; the apical margin concave, in

apical view cell bi-radiate.

Length: 21-23 µm, Breadth: 16-18 µm, Isthmus: 3-4 µm.

Collection No. DD- 387, 06.11.2009, Bitang cho Lake, Sikkim. In association

with greenish-brown scum on the surface of the wet rock (pH 6, temp 10ºC).

Indian distribution: Assam (Carter 1926); Ahmadabad (Kamat 1962), Pakhal

Lake, Andhra Pradesh (Suxena & Venkateswarlu 1966a); Gwalior, Madhya

Pradesh (Agarkar 1971); Hyderabad (Munawar 1974; Rao 1975); Nagpur (Freitas

& Kamat 1979); Allahabad (Pandey & Pandey 1980); Kashmir (Compère 1983);

Gujarat (Kumar & Patel 1990b); Kolhapur, Maharashtra (Leela et al. 2012).

XVII. Teilingia Bourrelly

Cells small, more or less flattened, with deep median constriction, shaped compressed

elliptic or quadrangular, united into filaments, apex flat, bearing on the outer margin a

pair of small granules, granules may be present on the lateral walls or on the face of

the semicells, rarely granules replaced by short spines, cells united end to end with

those apical granules. Cells wall without any further ornamentations; chloroplast

single, axial with single pyrenoids in each semicell.

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Key to the taxa investigated:

1. Lateral margins of semicells smooth, sinus shallow………...….....…(1) T. excavata

1. Lateral margins with 3 granules, sinus rather deep…………......…..(2) T. granulata

1. Teilingia excavata (Ralfs) Bourelly var. excavata

(Lenzenweger 1997, p. 147, pl. 43, f. 24; Croasdale et al. 1983, p. 7, pl. 450, f. 1-

5)

[Pl. XXVI, f. 433, 434]

Cells small, as long as broad; sinus openly wide with obtuse interior; apex

flattened, bearing 4 very small, widely spread granule like ‘connecting processes’;

semicells broadly oval in face view; cell wall smooth; cells joined end to end

loosely by connecting processes forming short pseudo-filament.

Length: 7-8 µm, Breadth: 7-8 µm, Isthmus: 5-7 µm.

Collection No. DD-418, 06.11.2009, Mamencho Lake, Sikkim. In association

with green filaments on the surface of the water (pH 6, temp 10ºC).

Indian distribution: Kashmir (Compère 1983).

This is the first report of the taxon from Eastern Himalaya.

2. Teilingia granulata (Roy et Bisset) Bourrelly

(Lenzenweger 1997, p. 148, pl. 43, f. 23; Croasdale et al. 1983, p. 9, pl. 451, f. 3-

5)

[Pl. XXVI, f. 431, 432]

Cells smooth, slightly broader than long, flatly rounded at the apex, which bears 4

granules, moderately deeply incised, the sinus widely open, rounded in the

interior; semicells oblong, lateral margins rounded, bearing a clusters of small

granules, usually 3 marginal ones only; remaining wall smooth; cells attached end

to end by the apical granules to form long filaments.

Length: 13-15 µm, Breadth: 12-14 µm, Apex: 6-7 µm, Thickness: 8-9 µm.

Collection No. DD-379, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with light green filaments floating freely on the surface of the water o(pH, 6 temp

10ºC).

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Indian distribution: Kashmir (Compère 1983); Kolhapur, Maharashtra (Leela et

al. 2012).

This is the first report of the taxon from Eastern Himalaya.

XVIII. Triplastrum Iyengar et Ramanathan

Cells solitary, cylindrical with slight median constriction, 6-8 times longer than broad,

poles truncate, at the apex 3 short lobes each bearing 1-4 spines; chloroplast stellate or

axial plate with longitudinal ridges and 2-4 pyrenoids in each semicells.

1. Triplastrum abbreviatum (Turner) Iyengar et Ramanathan

(Iyengar & Ramanathan 1942, p. 228, f. 6)

[Pl. XXVI, f. 429, 430]

Cells with a shallow median constriction, semicells straight 6-8 times longer than

broad, cylindrical end truncated and inflated forming 3 shallow lobes; each

bearing single spines; chloroplast stellate in median series, pyrenoids 2 in each

semicells.

Length: 79-82 µm. Breadth: 7-8 µm.

Collection No. DD-582, 10.11.2009, Sungure, Sikkim. In association with

greenish-brown mucilaginous mass hanging from rock wall beside a small

waerfalls (pH 6, temp. 16ºC).

Indian distribution: South India (Iyengar & Ramanathan 1942).

This is the first report of the taxon from Eastern Himalaya.

XIX. Triploceras Bailey

Cells solitary, elongate, sub-cylindrical 8-20 times longer than broad with shallow

median incision, only slightly tapering to the apex, lateral margins undulate with

several whorls of mamillate protuberances, each bearing a simple or bifid short spines

sometimes an emarginate verruca. Apex truncate, sometimes concave and 2-4 furcate,

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usually with two spines on each apical process. Chloroplast axial, single in each

semicells, stellate in end view with axial row of pyrenoids. Chloroplast with

longitudinal lamellae.

1. Triploceras gracile Bailey var. gracile

(Krieger 1937, p. 442, pl. 52, f. 1-7; Prescott et al. 1975, p. 143, pl. 51, f. 7-14)

[Pl. XXVI, f. 419, 420]

Cells elongate, subcylindric, 10-11 times longer than broad; semicells slightly

tapered from base to apex, with 9 whorls of 13 low, mammilate spine; spines in

upper few whorls directed upward, in lower whorls outward or straight; apex

divided into 3 short processes each tipped with paired short spines; usually a pair

of blunt spines between the primary forks.

Length: 450-457 µm, Breadth: 43-45 µm, Apex: 26-32 µm.

Collection No. DD-382, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with green filamentous mass attached to the surface of the submerged aquatic

plants (pH 6, temp 10ºC).

Indian distribution: Eastern India (Turner 1892); Tamilnadu (Ramanathan

1962); Karnataka (Bharati 1965b; Gurudeva et al. 1983); West Bengal (Mallick &

Keshri 2009).

This is the first report of the taxon from Eastern Himalaya.

XX. Xanthidium Ehrenberg ex Ralfs

Cells solitary, slightly compressed, with deep median constriction in the midregion.

Semicells ellipsoidal, polygonal, oval, rarely triangular. Each semicell usually with 2-

4 or more simple or furcated, short or long, stout, sometimes blunt spines, laterally

aligned, usually in pairs. Face of the semicells usually smooth, sometimes with small

protuberance having rings of small pores or a protuberance bearing short or long

spine. Cell wall thick and generally smooth but sometimes with scattered pores.

Chloroplast 2 in each semicells with one or more pyrenoid.

Key to the taxa investigated:

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1. Face of the semicells smooth, semicells sub-elliptic-hexagonal, spines long

2. Semicells sub-elliptical, basal and apical angles with a pair of spines

...…(2) X. antilopaeum var. antilopaeum f. antilopaeum

2. Semicells sub-elliptic-haxagonal, apical angles having a pair of spines but basal

angles having a single spine instead lateral walls having a pair of spines

…..….(3) X. antilopaeum var. antilopaeum f. javonicum

1. Face of the semicells with scatteredly placed pores, semicells oval

………………………………...…(1) X. acanthophorum

1. Xanthidium acanthophorum Nordstedt

(Ling & Tyler 1986, p. 56, pl. 23, f. 4-6)

[Pl. XXVIII, f. 492, 493]

Cells medium sized, 1.1-1.2 times longer than broad; semicells oval, median

constriction deep, the sinus open, acute angled; lateral margin slightly convex and

very slightly attenuated at the apex, furnished with 4 long blunt spines in each side

which are in pairs, spines slightly curved; apex flat, also having two pairs of long,

straight blunt spines leaving the central space; face of the semicells having several

pores scatteredly arranged in the centre; chloroplast 2 per semicells.

Length: 52-55 µm (with spines), 42-45 µm (without spines); Breadth: 42-46µm

(with spines), 32-35 µm (without spines), Isthmus: 14-16 µm.

Collection No. DD-130, Khechiperi Lake, Sikkim. In association with green

filaments growing attached on pebbles & submerged weeds from a drain beside

the Lake (pH 4.5, temp. 17ºC).

Indian distribution: Eastern India (Turner 1892); Gwalior, Madhya Pradesh

(Agarkar 1969).

This is the first report of the taxon from Eastern Himalaya.

2. Xanthidium antilopaeum (Brébisson) Kutzing

(West & GS West 1912, p. 63, pl. 108, f. 7-18; Prescott et al. 1982, p. 46, pl. 311,

f. 7, 8; pl. 317, f. 8; Lenzenweger 1997, p. 9, pl. 18, f. 11-13, pl. 19, f. 1, 2)

[Pl. XXIX, f. 494, 495]

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Cells medium sized, slightly broader than long; median constriction deep, sinus

linear, closed; semicells subelliptic-hexagonal, angles slightly rounded, each of

the four exposed angles furnished with a pair of simple, straight, long spines;

apex slightly retuse.

Length: 61-63 µm (with spines), 42-44 µm (without spines); Breadth: 71-74µm

(with spines), 49-51 µm (without spines), Isthmus: 20-22 µm.

Collection No. DD-398, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with light green filaments on the surface of the water (pH 6, temp. 10ºC).

Indian distribution: Kodaikanal, (Bharati & Pai 1972); Allahabad (Pandey &

Pandey 1980); Namchi, Sikkim (Santra & Pal 2006); Muriyad, Kerala

(Sanilkumar & Thomas 2006).

3. Xanthidium antilopaeum (Brébisson) Kutzing var. antilopaeum f. javonicum

Nordstedt

(Prescott et al. 1982, p. 47, pl. 314, f. 2)

[Pl. XXIX, f. 496-498]

Cells medium sized, subelliptical-hexagonal, very slightly longer than broad,

median constriction deep, sinus linear, acute angled, closed but open in the outer

half; lateral walls and apex retuse; angles slightly rounded; semicells have 4 stout,

straight spines on each lateral margin, 2 spines inserted at the upper angles,

normally attached side by side and other 2 approximately near the lateral angles

and disposed about in a median vertical plane; the basal angles having only one

spine.

Length: 61-64 µm (with spines), 43-46 µm (without spines); Breadth: 58-61µm

(with spines), 40-43 µm (without spines), Isthmus: 17-18 µm.

Collection No. DD-380, 06.11.2009, Bitang-cho Lake, Sikkim. In association

with green scum in a swamp (pH 6, temp. 10ºC).

Indian distribution: Bombay & Karnatak (Bharati 1966).

This is the first report of the taxon from Eastern Himalaya.

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General Discussion

and Conclusion

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GENERAL DISCUSSION AND CONCLUSION

223

GENERAL DISCUSSION AND CONCLUSION

During the present systematic investigation on desmid biodiversity of certain regions

of Eastern Himalaya emphasis has been given to explore the accessible water bodies

of entire Sikkim state and certain parts of northern region of West Bengal like

Kalimpong, Lava and Lolegaon etc.

Desmids including phytoplankton serve as primary producer in food chain. Those

photosynthetic green and blue-green algae contribute about 70% oxygen productions

on the Earth. They also contribute in the pedogenesis from soil surface including the

biomass addition on soil. Desmid in particular can serve as indicator of water

pollution. They can be used as typification of water bodies (Brook 1981). It is well

known that desmids prefer little acidic and unpolluted environment. Any minor

change in water chemistry or slight pollution may lead to the reduction in their

availability.

In spite of long exploration works initiated by botanist like Joseph Dalton Hooker

many localities of Sikkim are unexplored phycologically. The target of present

investigation was to explore these minute organisms in view that (i) they will be

available in most of the habitats, (ii) to explore their biodiversity in Eastern

Himalayas, (iii) since tourist activity has changed the scenario whether any

degradation occurred?

Since the lakes of Sikkim were expected to have good cosmos of phyco-flora they

were targeted first. Local peoples of Eastern Himalaya mainly in Sikkim consider

lakes as sacred and monks even don’t allow outsiders to touch the holy water in some

places. In this regard there were several problems in field collection of water samples

from those lakes and water bodies. Therefore several collections were made through

local peoples from several remote places. Difficulties were also faced in the border

regions due to security problems.

As desmids are fresh water members and lodged on the aquatic or semi-aquatic weeds

including the mosses, bog pool proved the better inhabitant of desmid vegetation.

Desmid species were found in association with wet mosses growing on wet soil or

rock surface also. It is observed in present investigation that little acidic pH (5-6.5)

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GENERAL DISCUSSION AND CONCLUSION

224

situations of bogs support the better availability of desmids as also reported by early

workers. It is also observed in present study that lakes and water bodies that have

forest canopy in and around or having successive weed vegetation besides its margins

are found to be better occupant of desmids as well as other microalgae as compared to

those water bodies having lesser vegetation. This is why Mamencho Lake that have

forest canopy around the lake creating shady, wet environment provided suitable

atmosphere for the growth of the phytoplankton. Bitang-cho Lake, Khechiperi Lake

and few small water bodies in Pelling and Kalimpong have sufficient weed and moss

vegetation in their margins that proved suitable for desmid growth. Conversely,

Changu Lake and Gurudongmar Lake are very poor with plant and weed vegetation

and few members of desmids as well as other phytoplankton were reported in these

lakes. In case of Gurudongmar Lake having an altitude of 17,800 ft, there is no

vegetation at all around the lake in such an altitude. Those regions are considered as

‘cold desert’. Although few members of Closterium, Cosmarium, species of

Oedogonium and Spirogyra have been recorded in this lake. Very interesting

character reported in Kothak Lake, Yoksum, and West Sikkim. This lake having very

less vegetation around it but various members of order Chlorococcales mainly

Scenedesmus and Oocystis reported from its water. It appears to be an indicator of

increasing pollution load. Interestingly water having poor representation of desmids.

Further detailed limnological study may explain these observations. Delo reservoir in

Kalimpong is polluted by external activities. Naturally desmid and other

phytoplankton vegetation were found scanty in number.

Following are some graphical representations of the individuals of algae in

comparison to desmids reported in major investigated lakes of Sikkim and adjoining

regions.

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GENERAL DISCUSSION AND CONCLUSION

225

Graph I: Graphical representation of desmid members recorded from Mamencho

Lake as compared to other major groups of algae.

Graph II: Graphical representation of desmid members recorded from Bitang-cho

Lake as compared to other major groups of algae.

0

10

20

30

40

50

60

70

80

Cyanophyceae

Chlorophyceae

Diatoms

Desmids

0

10

20

30

40

50

60

70

80

90

100

Cyanophyceae

Chlorophyceae

Diatoms

Desmids

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GENERAL DISCUSSION AND CONCLUSION

226

Graph III: Graphical representation of desmid members recorded from Khechiperi

Lake as compared to other major groups of algae.

Graph IV: Graphical representation of desmid members recorded from Changu Lake

as compared to other major groups of algae.

0

5

10

15

20

25

Cyanophyceae

Chlorophyceae

Diatoms

Desmids

0

2

4

6

8

10

12

14

16

18

Cyanophyceae

Chlorophyceae

Diatoms

Desmids

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GENERAL DISCUSSION AND CONCLUSION

227

Graph V: Graphical representation of desmid members recorded from Gurudongmar

Lake as compared to other major groups of algae.

Graph VI: Graphical representation of desmid members recorded from Kothak Lake

as compared to other major groups of algae.

0

1

2

3

4

5

6

7

Cyanophyceae

Chlorophyceae

Diatoms

Desmids

0

5

10

15

20

25

30

35

Cyanophyceae

Chlorophyceae

Diatoms

Desmids

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GENERAL DISCUSSION AND CONCLUSION

228

Streams, rivers and waterfalls were found in having very poor phytoplankton

vegetation although some diatoms were observed. However, several members of

desmids as well as other phytoplankton found from rock-pools besides the streams

and waterfalls. Few members were recorded also from mucilage hanging from the

rock walls besides the small waterfalls along with other cyanophycean members. It is

also reported that desmids may found in association with other green algal

filamentous algal bloom such as Spirogyra, Mougeotia etc.

About 1000 algal samples were collected from different localities and almost all

possible habitats in the certain parts of Eastern Himalaya. From those about 650

camera-lucida drawings have been made and their photo-micrographs were taken,

from which 272 taxa under 27 genera of desmid have been identified; 25 taxa under 7

genera of Saccoderm desmids (Mesotaeniaceae) and 247 taxa under 20 genera

belonging to Placoderm desmids (Gonatozygaceae, Peniaceae, Closteriaceae and

Desmidiaceae).

Following is the list of desmids observed indicating their availability:

No. Name of the genera No. of taxa

reported in

the present

investigatio

n

Taxa new

to

Eastern

Himalaya

Taxa

new to

India

New to science

Species Variety Total

no. of

new

taxa

1 Actinotaenium C

9 8 3 1 1

2 Ancylonema RR

1 1 1

3 Arthrodesmus C

4 4 3

4 Closterium CC

64 27 15 6 5 11

5 Cosmarium CC

81 43 21 7 5 12

6 Cylindrocystis C

4 2 1

7 Desmidium C

3 1 1

8 Euastrum CC

18 15 9

9 Genicularia R

1 1 1

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GENERAL DISCUSSION AND CONCLUSION

229

10 Gonatozygon C

4 2 2

11 Haplotaenium R

1 1 1

12 Hyalotheca C

3 2

13 Mesataenium C

5 5 2

14 Micrasterias C

9 5

15 Netrium C

10 8 5

16 Onychonema R

2 1

17 Penium C

5 4 4

18 Pleurotaenium C

14 12 7

19 Roya R

2 2 2

20 Spirotaenia R

1 1

21 Spondylosium C

2 1

22 Staurastrum CC

20 19 7

23 Teilingia C

2 2

24 Tortitaenia R

2 1 1

25 Triplastrum R

1 1

26 Triploceras RR

1 1

27 Xanthidium C 3 2

Total 272 172 86 14 10 24

RR = Very Rare

R = Rare

C = Common

CC = Very Common

Total 232 desmid taxa were reported by earlier workers (Dickie1882, Prasad & Misra

1987, Rout & Gaur 1994, Gupta 2002, Kumar & Rai 2005, Santra & Pal 2006,

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GENERAL DISCUSSION AND CONCLUSION

230

Suseela & Toppo 2006, Bhakta et al. 2010, Deca et al. 2011, Yasmin et al. 2011, Das

& Keshri 2012) from different regions of Eastern Himalaya.

Graph VI: Graphical representation of desmid taxa reported by earlier workers and in

the present study.

Chart I: Pie chart showing genus-wise taxa recorded in the present study from

Eastern Himalaya.

210

220

230

240

250

260

270

280

Desmid taxa reported

by early workers

Desmid taxa recorded

in the present study

Desmid taxa reported by

early workers

Desmid taxa recorded in

the present study

Actinotaenium

Ancylonema

Arthrodesmus

Closterium

Cosmarium

Cylindrocystis

Desmidium

Euastrum

Genicularia

Gonatozygon

Haplotaenium

Hyalotheca

Mesataenium

Micrasterius

Netrium

Onychonema

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GENERAL DISCUSSION AND CONCLUSION

231

Out of 272 taxa 24 taxa under 3 genera were described as new to science. In addition,

one new combination has been proposed in the genus Cosmarium [C. cohnii (Nobilis)

Keshri et Das comb. nov.]. 6 genera (Ancylonema, Roya, Spirotaenia, Teilingia,

Triplastrum and Triploceras) are new addition to the desmid flora of Eastern

Himalaya. 86 taxa under 18 genera are new addition to Indian desmid flora, and 172

taxa are new addition to Eastern Himalaya desmid flora.

From the above findings it is clear that Eastern Himalaya is very extremely rich in

desmid vegetation as well as other phytoplankton. Further continued systematic

investigation may contribute our knowledge about algal population of Eastern

Himalaya. Also detailed limnological study on different water bodies may explain the

correlation between availability of phytoplankton in relation to environmental

conditions.

From this investigation following inferences have been made:

1. There is a serious lacuna in the exploration of phyco-flora in concern.

2. Identification part of the available literature on phytoplankton is to be reassessed.

3. Exploration of the lakes and water bodies in Eastern Himalaya need urgent

attention since the available data may help to protect these water bodies in addition

to the welfare of the local inhabitants.

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Figures

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PLATE I

1. Ancylonema nordenskioeldii

2. Ancylonema nordenskioeldii

3. Cylindrocystis crassa var. crassa

4. Cylindrocystis brebisonii var.

brebisonii

5. Cylindrocystis brebisonii var.

brebisonii

6. Cylindrocystis brebisonii var. minor

7. Cylindrocystis brebisonii var. minor

8. Cylindrocystis brebisonii var.

jenneri

9. Cylindrocystis brebisonii var.

jenneri

10. Mesotaenium macrococcum var.

macrococcum

11. Mesotaenium macrococcum var.

macrococcum

12. Mesotaenium degreyii var. breve

13. Mesotaenium chlamydosporum var.

violascens

14. Mesotaenium chlamydosporum var.

violascens

15. Mesotaenium macrococcum var.

minus

16. Mesotaenium chlamydosporum var.

violascens

17. Mesotaenium chlamydosporum var.

violascens

18. Mesotaenium chlamydosporum var.

chlamydosporum

19. Mesotaenium chlamydosporum var.

chlamydosporum

20. Mesotaenium macrococcum var.

minus

21. Tortitaenia alpina

22. Tortitaenia obscura

23. Tortitaenia obscura

24. Tortitaenia obscura

25. Roya obtusa var. obtusa

26. Roya obtusa var. obtusa

27. Roya obtuse var. montana

28. Roya obtusa var. montana

29. Spirotaenia condensata

30. Spirotaenia condensata

31. Spirotaenia condensata

32. Spirotaenia condensata

33. Netrium digitus var. curtum

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PLATE II

34. Netrium digitus var. naegelii

35. Netrium digitus var. digitus

36. Netrium digitus var. rectum

37. Netrium oblongum var. oblongum

38. Netrium interruptum var. minor

39. Netrium interruptum var. sectum

40. Netrium interruptum var. sectum

41. Netrium oblongum var.

cylindricum

42. Netrium oblongum var.

cylindricum

43. Netrium oblongum var.

acuminatum

44. Netrium oblongum var.

acuminatum

45. Netrium oblongum var.

acuminatum

46. Netrium minus

47. Actinotaenium australe

48. Actinotaenium australe

49. Actinotaenium capax var. minus

50. Actinotaenium capax var. minus

51. Actinotaenium sikkimicum sp. nov.

52. Actinotaenium sikkimicum sp. nov.

53. Actinotaenium subglobosum

54. Actinotaenium subglobosum

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PLATE III

55. Actinotaenium subglobosum

56. Actinotaenium curtum var. curtum

f. minus

57. Actinotaenium curtum var. curtum

f. minus

58. Actinotaenium curtum var. curtum

f. minus

59. Actinotaenium globosum var.

globosum

60. Actinotaenium cucurbitinum var.

cucurbitinum f. minutum

61. Actinotaenium cucurbita var.

cucurbita f. rotundatum

62. Actinotaenium diplosporum var.

americanum

63. Arthrodesmus convergens var.

convergens

64. Arthrodesmus convergens var.

convergens

65. Arthrodesmus convergens var.

convergens

66. Arthrodesmus extensus var.

extensus

67. Arthrodesmus extensus var.

extensus

68. Arthrodesmus convergens var.

incrassatus

69. Arthrodesmus convergens var.

incrassatus

70. Arthrodesmus curvatus var.

americanus

71. Arthrodesmus curvatus var.

americanus

72. Arthrodesmus curvatus var.

americanus

73. Arthrodesmus curvatus var.

americanus

74. Cosmarium cyclicum var. crassum

75. Cosmarium subquadratum

76. Cosmarium quadratum var.

quadratum f. boreale

77. Cosmarium quadratum var.

quadratum f. willei

78. Cosmarium pseudoexiguum

79. Cosmarium yoksomum sp. nov.

80. Cosmarium granatum var.

elongatum

81. Cosmarium vittanum

82. Cosmarium angulatum f. major

83. Cosmarium angulatum f. major

84. Cosmarium angulatum f. major

85. Cosmarium naegelianum

86. Cosmarium naegelianum

87. Cosmarium garrolense var.

garrolense f. dimidio-minus

88. Cosmarium garrolense var.

garrolense f. dimidio-minus

89. Cosmarium galeritum var.

subtumidum

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PLATE IV

90. Cosmarium galeritum var.

subtumidum

91. Cosmarium galeritum var.

subtumidum

92. Cosmarium levinotabile

93. Cosmarium garrolense

94. Cosmarium undulatum var. wollei

95. Cosmarium undulatum var. wollei

96. Cosmarium minimum var.

subrotundum

97. Cosmarium minimum var.

subrotundum

98. Cosmarium impressulum var.

suborthogonum

99. Cosmarium impressulum var.

suborthogonum

100. Cosmarium impressulum var.

suborthogonum

101. Cosmarium impressulum var.

suborthogonum

102. Cosmarium cymatopleurum

103. Cosmarium portianum var.

nephroideum

104. Cosmarium portianum var.

nephroideum

105. Cosmarium cycladatum

106. Cosmarium cycladatum

107. Cosmarium contractum var.

minutum

108. Cosmarium contractum var.

minutum

109. Cosmarium contractum var.

minutum

110. Cosmarium contractum var.

minutum

111. Cosmarium moniliforme var.

moniliforme

112. Cosmarium pakistanicum

113. Cosmarium pakistanicum

114. Cosmarium tyrolicum

115. Cosmarium pseudodebaryi sp.

nov.

116. Cosmarium pseudodebaryi sp.

nov.

117. Cosmarium undulatum var.

alaskanum f. reductum

118. Cosmarium undulatum var.

alaskanum f. reductum

119. Cosmarium undulatum var.

alaskanum f. reductum

120. Cosmarium undulatum var.

alaskanum f. reductum

121. Cosmarium hammeri var.

protuberans

122. Cosmarium hammeri var.

protuberans

123. Cosmarium depressum var.

depressum f. minutum

124. Cosmarium hammeri var.

hammeri

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PLATE V

125. Cosmarium cohnii comb. nov.

126. Cosmarium cohnii comb. nov.

127. Cosmarium connatum var.

connatum

128. Cosmarium connatum var.

connatum

129. Cosmarium amoenum var.

intumescens

130. Cosmarium botrytis var.

mediolaeve

131. Cosmarium pseudocyclicum sp.

nov.

132. Cosmarium pseudocyclicum sp.

nov.

133. Cosmarium pseudamoenum

134. Cosmarium pseudamoenum

135. Cosmarium granatum var.

subangulare

136. Cosmarium granatum var.

granatum

137. Cosmarium granatum var.

granatum

138. Cosmarium granatum var.

granatum

139. Cosmarium hammeri var.

schmidlei

140. Cosmarium rosae

141. Cosmarium rosae

142. Cosmarium montrealense

143. Cosmarium phaseolus var.

phaseolus f. minus

144. Cosmarium pseudo-obsoletum sp.

nov.

145. Cosmarium connatum var.

depressum

146. Cosmarium transitorium

147. Cosmarium moniliforme forma

148. Cosmarium laeve var.

octangulare

149. Cosmarium subcucumis var.

subcucumis

150. Cosmarium subcucumis var.

subcucumis

151. Cosmarium subcucumis var.

subcucumis

152. Cosmarium subcucumis var.

subcucumis

153. Cosmarium quadrum var. minus

154. Cosmarium reniforme var. minor

155. Cosmarium reniforme var. minor

156. Cosmarium quadrum var.

quadrum

157. Cosmarium quadrum var.

quadrum

158. Cosmarium subcrenatum

159. Cosmarium sinostegos

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PLATE VI

160. Cosmarium quadrum var.

quadrum

161. Cosmarium quadrum var.

quadrum

162. Cosmarium longicylindricum var.

indicum

163. Cosmarium longicylindricum var.

indicum

164. Cosmarium garrolense var. minus

165. Cosmarium garrolense var. minus

166. Cosmarium pyramidatum var.

indicum var. nov.

167. Cosmarium pyramidatum var.

indicum var. nov.

168. Cosmarium pyramidatum var.

indicum var. nov.

169. Cosmarium undulatum var.

indicum var. nov.

170. Cosmarium undulatum var.

indicum var. nov.

171. Cosmarium nitidulum

172. Cosmarium nitidulum

173. Cosmarium javanicum

174. Cosmarium javanicum

175. Cosmarium pseudolundellii sp.

nov.

176. Cosmarium phaseolus var.

phaseolus

177. Cosmarium subtumidum

178. Cosmarium subtumidum

179. Cosmarium subphaseolanum sp.

nov.

180. Cosmarium subphaseolanum sp.

nov.

181. Cosmarium coarctatum

182. Cosmarium coarctatum

183. Cosmarium pseudopyramidatum

184. Cosmarium pseudopyramidatum

185. Cosmarium ornatum var.

sikkimicum var. nov.

186. Cosmarium ornatum var.

sikkimicum var. nov.

187. Cosmarium portianum forma

188. Cosmarium portianum forma

189. Cosmarium baffinense

190. Cosmarium baffinense

191. Cosmarium dorsitruncatum var.

pseudoscenedesmus

192. Cosmarium dorsitruncatum var.

pseudoscenedesmus

193. Cosmarium portianum

194. Cosmarium portianum

195. Cosmarium portianum

196. Cosmarium tithophorum

197. Cosmarium tithophorum

198. Cosmarium trilobulatum

199. Cosmarium sikkimicum sp. nov.

200. Cosmarium sikkimicum sp. nov.

201. Cosmarium favum var. indicum

var. nov.

202. Cosmarium favum var. indicum

var. nov.

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PLATE VII

203. Cosmarium lundelli var.

ellipticum

204. Cosmarium lundelli var.

ellipticum

205. Cosmarium obsoletum

206. Cosmarium obsoletum

207. Cosmarium nudum

208. Cosmarium nudum

209. Cosmarium undulatum var.

minutum

210. Cosmarium undulatum var.

minutum

211. Cosmarium impressulum var.

impressulum

212. Cosmarium impressulum var.

impressulum

213. Cosmarium depressum var.

reniforme

214. Cosmarium depressum var.

reniforme

215. Cosmarium retusiforme

216. Cosmarium retusiforme

217. Cosmarium regnesi

218. Cosmarium regnesi

219. Staurastrum striolatum var.

striolatum f. brasiliense

220. Staurastrum striolatum var.

striolatum f. brasiliense

221. Staurastrum striolatum var.

striolatum f. brasiliense

222. Staurastrum bieneanum var.

bieneanum

223. Staurastrum muticum var.

muticum f. minus

224. Staurastrum muticum var.

muticum f. minus

225. Staurastrum muticum var.

muticum f. minus

226. Staurastrum botanense var.

botanense

227. Staurastrum botanense var.

botanense

228. Staurastrum botanense var.

botanense

229. Staurastrum longibrachiatum

230. Staurastrum longibrachiatum

231. Staurastrum sonthalianum

232. Staurastrum sonthalianum

233. Staurastrum orbiculare var.

minor

234. Staurastrum orbiculare var.

minor

235. Staurastrum orbiculare var.

minor

236. Staurastrum dejectum var. patens

237. Staurastrum dejectum var. patens

238. Staurastrum dejectum var. patens

239. Staurastrum habeebense

240. Staurastrum habeebense

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PLATE VIII

241. Staurastrum duplex

242. Staurastrum duplex

243. Staurastrum duplex

244. Staurastrum bifidum

245. Staurastrum bifidum

246. Staurastrum talisheekense

247. Staurastrum talisheekense

248. Staurastrum talisheekense

249. Staurastrum lapponicum

250. Staurastrum lapponicum

251. Staurastrum punculatum var.

subproductum

252. Staurastrum punculatum var.

subproductum

253. Staurastrum orbiculare

254. Staurastrum orbiculare

255. Staurastrum bieneanum var.

bieneanum

256. Staurastrum bieneanum var.

bieneanum

257. Staurastrum mamillatum

258. Staurastrum mamillatum

259. Staurastrum bieneanum var.

ellipticum

260. Staurastrum bieneanum var.

ellipticum

261. Staurastrum margaritaceum

262. Staurastrum margaritaceum

263. Staurastrum tetracerum var.

tetracerum

264. Staurastrum tetracerum var.

tetracerum

265. Staurastrum longibrachiatum var.

inflatum

266. Staurastrum longibrachiatum var.

inflatum

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PLATE IX

267. Closterium rectimarginatum

268. Closterium pritchardianum var.

pritchardianum f. attenuata

269. Closterium acerosum var.

tumidum

270. Closterium kuetzingii var.

kuetzingii

271. Closterium kuetzingii var.

kuetzingii

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PLATE X

272. Closterium lunula var. lunula f.

minor

273. Closterium lunula var. lunula f.

minor

274. Closterium mamenchoenum sp.

nov.

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PLATE XI

275. Closterium mamenchoenum sp.

nov.

276. Closterium striolatum var.

erectum

277. Closterium striolatum var.

erectum

278. Closterium subjuncidiforme

279. Closterium subjuncidiforme

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PLATE XII

280. Closterium subjuncidiforme

281. Closterium subjuncidiforme

282. Closterium subjuncidiforme

283. Closterium rectimarginatum

forma

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PLATE XIII

284. Closterium ehrenbergii var.

malinvernianum

285. Closterium ehrenbergii var.

malinvernianum

286. Closterium abruptum var. brevius

287. Closterium abruptum var. brevius

288. Closterium ehrenbergii var.

malinvernianum

289. Closterium ehrenbergii var.

malinvernianum

290. Closterium subcosticum

291. Closterium subcosticum

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PLATE XIV

292. Closterium striolatum var.

subtruncatum

293. Closterium striolatum var.

subtruncatum

294. Closterium minutum var. indicum

var. nov.

295. Closterium minutum var. indicum

var. nov.

296. Closterium minutum var. indicum

var. nov.

297. Closterium dianae var. brevius

298. Closterium calosporum var.

calosporum f. erectum

299. Closterium parvulum var.

obtusum

300. Closterium parvulum var.

obtusum

301. Closterium venus var. crassum

302. Closterium parvulum var.

parvulum

303. Closterium parvulum var.

parvulum

304. Closterium navicula var. navicula

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PLATE XV

305. Closterium reticulatum sp. nov.

306. Closterium moniliferum var.

submoniliferum

307. Closterium moniliferum var.

submoniliferum

308. Closterium planum

309. Closterium planum

310. Closterium planum

311. Closterium planum

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PLATE XVI

312. Closterium ehrenbergii var.

ehrenbergii forma

313. Closterium ehrenbergii var.

ehrenbergii forma

314. Closterium libellula var.

sikkimense var. nov.

315. Closterium libellula var.

sikkimense var. nov.

316. Closterium tumidulum forma

317. Closterium tumidulum forma

318. Closterium littorale var. indicum

var. nov.

319. Closterium libellula var. libellula

f. libellula

320. Closterium libellula var. libellula

f. libellula

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PLATE XVII

321. Closterium eboracense

322. Closterium eboracense

323. Closterium ehrenbergii var.

ehrenbergii

324. Closterium dianae var. minor

325. Closterium dianae var. minor

326. Closterium libellula var.

intermedium

327. Closterium libellula var.

intermedium

328. Closterium tacomense

329. Closterium tacomense

330. Closterium acutum

331. Closterium acutum

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PLATE XVIII

332. Closterium pseudolunula

333. Closterium pseudolunula

334. Closterium pseudolunula

335. Closterium pseudolunula

336. Closterium arcuarium var.

sikkimense var. nov.

337. Closterium bitangchoianum sp.

nov.

338. Closterium bitangchoianum sp.

nov.

339. Closterium incurvum var.

incurvum

340. Closterium incurvum var.

incurvum

341. Closterium abruptum var.

abruptum

342. Closterium abruptum var.

abruptum

343. Closterium abruptum var.

abruptum

344. Closterium parvulum forma

345. Closterium parvulum forma

346. Closterium tumidulum

347. Closterium tumidulum

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PLATE XIX

348. Closterium lunula var. lunula

349. Closterium moniliferum var.

moniliferum

350. Closterium incurvum forma 1

351. Closterium elenkinii

352. Closterium elenkinii

353. Closterium cynthia var. cynthia

354. Closterium cynthia var. cynthia

355. Closterium cynthia var. cynthia

356. Closterium cynthia var. cynthia

357. Closterium gracile var. gracile

358. Closterium gracile var. gracile

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PLATE XX

359. Closterium ehrenbergii var.

podolicum

360. Closterium ehrenbergii var.

podolicum

361. Closterium subfusiforme

362. Closterium subfusiforme

363. Closterium calosporum var.

maius

364. Closterium calosporum var.

maius

365. Closterium pseudocynthia sp.

nov.

366. Closterium pseudocynthia sp.

nov.

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PLATE XXI

367. Closterium arcuarium var.

arcuarium

368. Closterium arcuarium var.

arcuarium

369. Closterium arcuarium var.

arcuarium

370. Closterium setaceum var.

setaceum

371. Closterium setaceum var.

setaceum

372. Closterium venus

373. Closterium venus

374. Closterium venus var. venus f.

minor

375. Closterium venus var. venus f.

minor

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PLATE XXII

376. Closterium parvulum var. maius

377. Closterium parvulum var. maius

378. Closterium rostratum var. sikkimicum var. nov.

379. Closterium rostratum var. sikkimicum var. nov.

380. Closterium sikkimicum sp. nov.

381. Closterium sikkimicum sp. nov.

382. Closterium pseudoincurvum sp. nov.

383. Closterium pseudoincurvum sp. nov.

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PLATE XXIII

384. Closterium rostratum var.

rostratum

385. Closterium rostratum var.

rostratum

386. Closterium rostratum var.

rostratum

387. Closterium striolatum var.

subdirectum

388. Closterium gracile var. tenue

389. Closterium gracile var. tenue

390. Closterium gracile var. tenue

391. Closterium gracile var. tenue

392. Closterium gracile var. tenue

393. Closterium eboracense forma

394. Closterium incurvum forma 2

395. Closterium incurvum forma 2

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PLATE XXIV

396. Pleurotaenium ehrenbergii var.

ehrenbergii f. rectum

397. Pleurotaenium ehrenbergii var.

ehrenbergii

398. Pleurotaenium ehrenbergii var.

ehrenbergii

399. Pleurotaenium subcoronulatum

var. subcoronulatum f. elongatum

400. Pleurotaenium ehrenbergii var.

crenulatum

401. Pleurotaenium ehrenbergii var.

crenulatum

402. Pleurotaenium truncatum var.

crassum f. crassum

403. Pleurotaenium truncatum var.

crassum f. crassum

404. Pleurotaenium trabecula var.

trabecula

405. Pleurotaenium repandum var.

repandum

406. Pleurotaenium repandum var.

repandum

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PLATE XXV

407. Pleurotaenium trabecula var.

elongatum

408. Pleurotaenium eugeneum

409. Pleurotaenium trabecula var.

trabecula

410. Pleurotaenium trabecula var.

trabecula

411. Pleurotaenium ehrenbergii var.

elongatum

412. Pleurotaenium ehrenbergii var.

elongatum

413. Pleurotaenium trabecula var.

hutchinsonii

414. Pleurotaenium trochiscum

415. Pleurotaenium trochiscum

416. Pleurotaenium nodosum var.

nodosum

417. Pleurotaenium nodosum var.

nodosum

418. Pleurotaenium trabecula var.

crassum

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PLATE XXVI

419. Triploceras gracile var. gracile

420. Triploceras gracile var. gracile

421. Penium exiguum var.

glaberrimum

422. Penium exiguum var.

glaberrimum

423. Penium margaritaceum var.

margaritaceum

424. Penium margaritaceum var.

margaritaceum

425. Penium margaritaceum var.

irregularius

426. Penium margaritaceum var.

punctatum

427. Penium margaritaceum var.

punctatum

428. Penium phymatosporum

429. Triplastrum abbreviatum

430. Triplastrum abbreviatum

431. Teilingia granulata

432. Teilingia granulata

433. Teilingia excavata

434. Teilingia excavata

435. Spondylosium nitens var.

triangulare

436. Spondylosium nitens var.

triangulare

437. Spondylosium planum var.

planum

438. Hyalotheca dissiliens var. hians

439. Hyalotheca dissiliens var. hians

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PLATE XXVII

440. Hyalotheca dissiliens var.

dissiliens

441. Hyalotheca dissiliens var.

dissiliens

442. Hyalotheca dissiliens var.

dissiliens

443. Hyalotheca dissiliens var.

dissiliens

444. Hyalotheca mucosa

445. Hyalotheca mucosa

446. Desmidium aptogonum var.

aptogonum

447. Desmidium aptogonum var.

aptogonum

448. Desmidium baileyi var. baileyi f.

minus

449. Desmidium baileyi var. baileyi f.

minus

450. Desmidium baileyi var.

tetragonum

451. Desmidium baileyi var.

tetragonum

452. Haplotaenium minutum var.

gracile

453. Genicularia elegans

454. Genicularia elegans

455. Gonatozygon monotaenium var.

monotaenium f. minutum

456. Gonatozygon monotaenium var.

monotaenium f. minutum

457. Gonatozygon aculeatum

458. Gonatozygon monotaenium var.

monotaenium f. punctatum

459. Gonatozygon monotaenium var.

monotaenium f. punctatum

460. Gonatozygon kinahani

461. Gonatozygon kinahani

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PLATE XXVIII

462. Euastrum oblongum

463. Euastrum humerosum

464. Euastrum platycerum var.

eximium f. clausum

465. Euastrum platycerum var.

eximium f. clausum

466. Euastrum spinulosum var.

spinulosum

467. Euastrum spinulosum var.

spinulosum

468. Euastrum spinulosum var. lindae

469. Euastrum spinulosum var. lindae

470. Euastrum subhypochondrum

471. Euastrum subhypochondrum

472. Euastrum ansatum var.

dideltiforme

473. Euastrum obesum var.

subangulare

474. Euastrum obesum var.

subangulare

475. Euastrum ansatum var. ansatum

476. Euastrum ampullaceum var.

incavatum

477. Euastrum ampullaceum var.

incavatum

478. Euastrum bidentatum var.

oculatum

479. Euastrum ciastonii var. ciastonii

480. Euastrum ciastonii var. ciastonii

481. Euastrum turnerii var. turnerii

482. Euastrum turnerii var. turnerii

483. Euastrum denticulatum var.

quadrifarium

484. Euastrum denticulatum var.

quadrifarium

485. Euastrum diplostauron

486. Euastrum diplostauron

487. Euastrum pseudocorralloides

488. Euastrum denticulatum var.

denticulatum f. glabrum

489. Euastrum denticulatum var.

denticulatum f. glabrum

490. Euastrum lütkemülleri var.

lütkemülleri

491. Euastrum lütkemülleri var.

lütkemülleri

492. Xanthidium acanthophorum

493. Xanthidium acanthophorum

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PLATE XXIX

494. Xanthidium antilopaeum

495. Xanthidium antilopaeum

496. Xanthidium antilopaeum var.

antilopaeum f. javonicum

497. Xanthidium antilopaeum var.

antilopaeum f. javonicum

498. Xanthidium antilopaeum var.

antilopaeum f. javonicum

499. Micrasterias foliacea var.

foliacea

500. Micrasterias foliacea var.

foliacea

501. Micrasterias mahabuleshwarensis

502. Micrasterias mahabuleshwarensis

503. Micrasterias ceratofera

504. Micrasterias ceratofera

505. Micrasterias alata

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PLATE XXX

506. Micrasterias alata

507. Micrasterias alata forma

508. Micrasterias alata forma

509. Micrasterias radians

510. Micrasterias radians

511. Micrasterias tropica

512. Micrasterias tropica

513. Micrasterias foliacea var.

foliacea

514. Micrasterias foliacea var.

foliacea

515. Micrasterias pinnatifida var.

pinnatifida

516. Micrasterias pinnatifida var.

pinnatifida

517. Micrasterias zeylanica

518. Micrasterias zeylanica

519. Onychonema laeve var.

micracanthum

520. Onychonema laeve var.

micracanthum

521. Onychonema laeve var. latum

522. Onychonema laeve var. latum