plant morphology. in flowering plants, fruit is a matured, ripened ovary that contains the seeds

Post on 28-Mar-2015

242 Views

Category:

Documents

4 Downloads

Preview:

Click to see full reader

TRANSCRIPT

Types of fruits

Plant morphology

In flowering plants, fruit is a matured, ripened ovary that contains the seeds

What is a fruit?

Three types:

Simple

Aggregate

Multiple

Types of fruits

develop from a single pistil Simple fruits can be either fleshy or dry when mature1. Fleshy

a. Berry: endocarp, mesocarp and exocarp are soft

Examples: Grapes, tomato.

Simple fruits

b. Drupe (stone fruit) : outer part of fruit wall is soft and fleshy, endocarp is hard.

Examples : apricot, nectarine, mango, olive, Plum, cherry, peach

c. Pome endocarp is papery or leathery most of the fleshy part of pomes develops from the enlarged

base of the perianth (corolla and calyx) that has fused with the ovary wall

Example: Apple and pear

d. Pepo also a fleshy fruit but exocarp is a tough has hard rind when mature

Examples: pumpkin, melons, cucumbers

2. Dry (when finished ripening) :Simple dry fruits are dry (not fleshy) at maturity.

a. Indehiscent (do not open when they dry) i. Achene : sunflower family, sedges

ii. Caryopsis: seed coat is fused to the ovary wallExample: cereal grains.

iii. Nut : single-ovary wall and seed coat remain separate, ovary wall is very hard E.g.: walnuts, chestnuts, acorns

b. Dehiscent (split open along one or more sutures). Simple dry fruits are dry (not fleshy) and open at maturity. Two Kinds:(1).Capsule – fruit is dry at maturity and splits open along

several seamsE.g.: Cotton, poppy

(2). Legumes – Legumes are dry at maturity and split open along one seams

E.g.: peas, beans and etc.

formed from a flower with numerous simple Pistils, all ripening simultaneously

E.g.: Blackberries, raspberries and strawberries

Aggregated fruits

formed from a cluster of flowers.

Multiple fruit develops from ovaries of several flowers

borne/fused together on the same stalk.

E.g.: Pineapple, mulberry, fig.

Multiple fruits

Dispersal of fruits and seeds

What is dispersal of seeds and fruits?

fall directly underneath the mother plant and the seedlings grow up close together

they soon exhaust the soil of its essential food constituents.

Besides, the availability space, light and air under such a condition fall far short of the demand.

A struggle for existence

they may easily fall prey to attacks by herbivorous animals.

Why dispersal?

Wings: develop one or more appendages in the form of thin, flat,

membranous wings, the seeds and fruits themselves are light and dry. help them float in the air and facilitate their dispersion by wind.

Parachute mechanism: calyx is modified into hair like structures known as pappus. is persistent in the fruit and opens out in an umbrella-like

fashion. gets detached from the parent plant, the pappus acts like a

parachute helps it float in the air.

Seeds and fruits dispersed by winds

Censer Mechanism the seeds of certain plants can be scattered by the wind only

after the dehiscence of the fruitHairs seeds are provided with hairs with either 1 or 2 tufts or all

over the body. hairs aids the distribution of seeds by the wind. Persistent Styles. the style are persistent and very feathery. The fruits are, thus, easily carried away by wind.Light Seeds and Fruits Some seeds and fruits are so light and minute in size that they

may easily be carried away by the gentlest breeze.

usually develop floating devices in the form of spongy or fibrous outer coats.

The fibrous fruit of coconut is capable of floating long distance in the sea without suffering any injury.

coconut is commonly seen on sea coasts and marine island.

Seeds and fruits Dispersed by water

Many fruit burst with a sudden jerk, with the result that the

seeds are scattered a few yards away from the parent plant.

Seeds Dispersed by Explosive Fruits

Hooked fruits: many fruits are provided with hooks, barbs, spines, bristles,

stiff hairs, etc, on their bodies by means of which they adhere to the bodies of woolly

animals as well as to the clothing of mankind unwittingly carried by them to distant places.

Sticky fruits: the fruits of Boerhavia and Plumbago have sticky glands on

their body. The seeds of mistletoe are very sticky.

Seeds and Fruits Dispersed by Animals

Fleshy fruits: many such fruits, coloured conspicuously, are carried

from one place to another for the sake of their beauty.

Edible fruits: human beings and birds are active and useful agents

in distributing such fruits. birds feed upon the pulpy portion of fruits like

guava, grape, fig, etc., and pass out the undigested seeds with the faeces.

Bats and squirrels are also useful in dispersing seeds and fruits.

top related