Plant Parts – Flowers

• Color• Shape• Size• Etc…

RANUNCULACEAE

Delphinium amplibracteatum

Ranunculus laetus

PAPAVERACEAEArgemone mexicana

Citrus aurantifolia

Murraya paniculata

RUTACEAE

Murraya koenigii

Citrus limon

LEGUMINOSAE

Lathyrus odoratus  

Pisum sativum

ROSACEAE

UMBELLIFERAE

Coriandrum sativum -

COMPOSITAE

ASCLEPIADACEAEAsclepias quinquedentata

Calotropis

SOLANACEAE Nicotiana glauca

Solanum nigrum

LAMIACEAE

Ocimun

EUPHORBIACEAE

Euphorbia hirta

Euphorbia pulcherime

POACEAE

Triticum aestivum

Oryza sativa

pistil

Flower parts:

• Perfect: both stamens & carpels

• Imperfect: missing either stamens or carpels• Monoecious: both

male & female flowers on same plant

• Dioecious: male & female flowers on separate plants The structure of a flower

femalemale

Embryo sac fruit

seed

monoecious species, male (left) and female (right) begonia flowers

Fig. 42.16

lily

Pollination Mechanisms

InsectsBees Butterflies/Moths Flies

BirdsBatsWaterWind

Bee-pollinate

d

Moth-pollinated

Fly-pollinated

Bird-pollinated

Bat-pollinated

Wind pollination in grasses

Phyllospadix torreyiSurf-Grass

Water-pollinated

Fig. 42.9

Fig. 42.10

Double fertilization in Angiosperms

Pollen produces

2 sperm cells:

Pollen produces 2 sperm cells:

sperm (n) + egg (n)----> zygote (2n)

sperm (n) + 2 polar nuclei (n)----> endosperm (3n)

Ovule to seed

Fruit = “mature ovary”purpose: protects seeds, dispersal

aid

Relationship between a pea flower and a fruit (pea pod)

Fruit Regions

Types of Fruits

• Dry fruits: Tough or papery pericarp• Dehiscent or indehiscent

• Fleshy fruits: Soft and juicy pericarp• Drupe• Berry• Aggregate• Multiple• Accessory

Development of fruit from flower

• simple = 1 ovary of 1 flower• e.g., cherry, soybean pod

• compound = multiple ovaries• aggregate = of one flower

• e.g., raspberry, blackberry

• multiple = of many flowers (inflorescence)

• e.g., pineapple

• accessory = parts other than ovary• e.g., strawberry, apple,

melon, tomato

•drupe

•berry

Fleshy Fruit

• E.g. Drupe - Simple fleshy fruit with a single seed enclosed by a hard, stony endocarp (pit).

Fruits

• Berry: Develops from a compound ovary. Contains more than one seed.• True berry: fruit

with a thin skin and soft pericarp (e.g. tomato).

Copyright © McGraw-Hill Companies PermissionRequired for Reproduction or Display

Berries

• Pepos - Thick skins/exocarps (Pumpkins).

Berries

• Hesperidium – Fruits with leathery exocarps containing oil glands (e.g. Citrus fruit).

Fruits

• Pomes – (not a true fruit)

• Pome: Accessory fruit with thick hypanthium.

• Bulk of flesh comes from enlarged floral tube or receptacle that grows up around the ovary. (Apples) Copyright © McGraw-Hill Companies Permission

Required for Reproduction or Display

Fruits

• Aggregate Fruits• Develop from a

single flower with numerous pistils.

Pistils mature as a clustered unit on a single receptacle

E.g. Raspberries, Strawberries.

                                                                                 

Fruits

• Multiple Fruits

• Develop from many individual flowers in a single inflorescence.

• E.g. Pineapples, Jackfruit

Dry Fruits - Dehiscent

• Follicle - Splits along one side/seam.

Dry Fruits - DehiscentLegume (e.g.

bean pod) • Consists of one

folded carpel• Splits along

two sides into 2 sections

• Each represents half the carpel.

• Some legume pods, such as carob and mesquite, are indehiscent and do not split open.

Dry Fruits - Dehiscent

• Capsules - Consist of at least two carpels, and split in a variety of ways.

Dry Fruits - Indehiscent

• Achene• Single seed attached to

pericarp • Pericarp fused into husk• Husk - Easily removed• Eg: buckweed, sunflower

seed

• Sunflower seed

Dry Fruits - Indehiscent

Nut• Single seed with hard

pericarp/husk• Cup or cluster of

bracts form at base• Hazel nuts: only true

nuts

• Walnuts, cashews & pecans = drupes

• Brazil nuts = seeds of capsules

Dry Fruits - Indehiscent

• Grain• One-seeded fruit/seed fused

with seed coat (pericarp)• Eg: wheat

Dry Fruits - Indehiscent

• Samara• Pericarp forms

wings• Fx: aids in seed

dispersal• Can be single or

double• Eg: Elm tree

Dry Fruits - Indehiscent

• Schizocarp

• Whole seed separates to form 2 separate 1-seeded fruitlets

• E.g.: Apiaceae/carrot family

Fig. 40.12

Fig. 40.13

Fig. 40.14

Fig. 40.2a

Fig. 40.2b

Cotyledons (embryonic leaves)

• Single cotyledon = monocot• Two large cotyledons = dicot

• Cotyledons can be “fleshy” or “leafy”

• Cotyledons can be kept belowground or elevated above ground

Fig. 40.7

Seed Germination

• imbibition: absorption of water

• mobilization of food reserves• enzyme activity

digests endosperm (converts starch to sugar)

Seed Germination• emergence of radicle– detects gravity & grows

downward

• epicotyl emerges through soil surface

• light cues upward & straighter growth

Fig. 40.1

With light:GreenShorterOpen cotyledonsStraight stem

Without light:YellowElongatedClosed cotyledonsHooked stem