photographic guide to the epiphytic orchids of the ......apr 01, 2015 · available, the new orchid...
TRANSCRIPT
Photographic Guide to the
Epiphytic Orchids of the
Aberfoyle Estate,
Honde Valley,
Zimbabwe
Peter Ashton
P.O. Box 905-502
Garsfontein West, 0042,
Pretoria, South Africa
(E-mail: [email protected])
Version 1 – April 2015
A Brief Introduction to this Guide
The Aberfoyle Estate is one of a group of active tea-
growing estates that occupy the picturesque northern
(upper) end of the Honde Valley in the Eastern Districts of
Zimbabwe. The estate is situated on the lower, eastern
slopes and foothills of Mount Nyangani, the highest peak in
Zimbabwe, with wonderful views towards Mozambique.
Mount Nyangani receives relatively high rainfall during the
summer months of each year and many perennial streams
and rivers drain the slopes, flowing towards the
Mozambique border. Frequent mists occur during the drier
winter months, providing an additional source of moisture to
the lush vegetation of the area.
The hill slopes are covered with dense stands of tall, moist
tropical woodland and forest, and the many waterways are
lined with lovely stands of riparian forest. The array of forest
and woodland habitats provides a range of suitable
environments for epiphytic orchids, and also for a wide
variety of bird, reptile, amphibian and butterfly species.
Epiphytic orchids grow on trees and occasionally on rocks,
anchoring themselves to their host tree (or rock) by a
network of roots. The orchids do not derive any nutrition
from the host tree and obtain the nutrients they need from
wind-blown dust, decaying bark and bird droppings. The
roots of epiphytic orchids are also able to absorb moisture
from mist in addition to any rainfall that is received during
the summer months.
In this guide, the nineteen epiphytic orchids that have so far
been recorded at the Aberfoyle Estate have been arranged
in alphabetical order for convenience. Photographs are
provided for each species, and brief notes are given on the
key characteristics that will help to confirm the identity of
the species.
This photographic guide has been compiled with the aim of
helping visitors to Aberfoyle to identify the commonest
epiphytic orchids that have been found on the estate. As
more orchid surveys are carried out in the different habitats
on the estate, it is inevitable that more species will be
recorded from time to time. As this information becomes
available, the new orchid records will be added to this guide
so that it remains as complete as possible.
Additional useful information on the orchids of Zimbabwe
can be found in the following publications:
• Ball, J.S. (1978). The Epiphytic Orchids of Southern
Africa, edited by Jane Browning. Conservation Press
(Pty) Ltd, Johannesburg, South Africa.
• La Croix, I.F. & Cribb, P.J. (1998). Orchidaceae – parts I
and II. In: Flora Zambesiaca, Volume 11, parts 1 and 2,
edited by G.V. Pope. Royal Botanic Gardens, Kew.
The publications listed above are sometimes difficult to
obtain and a very convenient option is to use the Zimbabwe
Flora website (http://www.zimbabweflora.co.zw). This
website contains an enormous amount of information on,
and photographs of, Zimbabwe’s orchid flora as well as
other plant families found throughout the country.
Aeranthes parkesii
Angraecopsis parviflora
Bulbophyllum encephalodes
Bulbophyllum longiflorum
Bulbophyllum maximum
Bulbophyllum sandersonii
Bulbophyllum unifoliatum
Cyrtorchis arcuata
Cyrtorchis praetermissa
Jumellea wallerii
Microcoelia exilis
Oberonia disticha
Polystachya albescens
Polystachya cultriformis
Polystachya mauritiana
Polystachya transvaalensis
Rangaeris muscicola
Tridactyle bicaudata
Tridactyle tridactylites