Biology Today - February 2018

• Ovary has one or more chambers or loculi (singular loculus) : unilocular (H.J.,pea); bilocular (H.J.,mustard); trilocular
  (H.J., $VSDUDJXV); tetralocular (H.J., 2FLPXP); pentalocular (H.J., China rose); multilocular (H.J., $OWKDHD, lady’s finger).


• In the chambers there are present oval outgrowths called ovules. Ovules later mature into seeds while the wall of the ovary
  forms a covering called pericarp. The two together constitute a fruit. A sterile and undeveloped pistil is called pistillode.

Types of style

Gynobasic

Style arising from the depression in the centre of

the ovary or directly from thalamus, H.J., 2FLPXP

Lateral

Style arising from the side of

the ovary, H.J., 3RWHQWLOOD

Terminal

Style lying in the same straight line

with the ovary, HJ+LELVFXV

Stylopodium : When base of the style is swollen to form a pad like structure, it is called stylopodium, H.J., Family

Apiaceae (Umbelliferae).

Plumose stigma : Feather like stigma is called plumose stigma, H.J., grasses.

Resupination : Turning or twisting of ovary of flower through 180°,L.H., upside down is called resupination, HJ, most orchids.

PLACENTATION

• Placenta is a parenchymatous cushion present inside the ovary where ovules are borne. An ovary may have one or more
  placentae. The number, position and arrangement or distribution of placentae inside an ovary is called placentation.

Types of

placentation

Parietal

Occurs in a bi-or multicarpellary syncarpous ovary. There are

two or more longitudinal placentae attached to the ovary

wall. Ovary can be unilocular or become falsely two or more

locular due to ingrowth of placentae or formation of false

septum, called replum, HJ members of Family Brassicaceae.

Ovary wall

Locule

Septum

Ovules

Superficial

Occurs in multicarpellary, multilocular

ovary. The ovules are borne on

placentae which develop all around

the inner surface of the partition wall,

HJ1\PSKDHD

Free central

The pistil is polycarpellary and

syncarpous but the ovary is

unilocular. The ovules are borne

around a central column which

is not connected with the ovary

wall by any septum, HJ

'LDQWKXV6LOHQH3ULPXOD, etc.

Ovary

Ovule

Basal

The pistil can be monocarpellary or

syncarpous. The ovary is unilocular.

It bears a single placenta at the base

with generally a single ovule, HJ

5DQXQFXOXV, Sunflower, marigold.

Marginal

Occurs in a monocarpellary,

unilocular ovary. The placenta

develops and ovules are borne

along the junction of the two

margins of the carpel, HJ

members of Family Leguminosae.

Axile

It occurs in polycarpellary syncarpous gynoecium. The ovary is many

chambered. The walls of the carpels in the centre of the ovary are

united to form an axis, which bears the placentae with ovules, HJ

3HWXQLD (bilocular), $VSKRGHOXV (trilocular), tomato (bi or tetralocular),

+LELVFXV (pentalocular), $OWKDHD and lemon (multilocular).

FRUIT

• True fruit or eucarp is a structure formed from ripened ovary under the influence of ripening ovules and is meant for protecting
  them. It consists of pericarp formed from the wall of the ovary and seeds formed from ovules. (.J., mango, brinjal, tomato,
  cucumber, pea, etc. When in formation of a fruit other floral parts, (HJ thalamus, base of sepal, petals, etc.) participate, it
  is called false fruit or pseudocarp,HJ apple, pear etc.


• A fruit formed without fertilisation LH., a seedless fruit is called parthenocarp, HJ., banana.

CLASSIFICATION OF FRUITS

• Based on the structure of pericarp, mode of dehiscence and the ovary from which they have developed, fruits are of mainly three types.

Types of fruits

Composite fruits

Develop from the complete

inflorescence.

Aggregate fruits

Develop from the multicarpellary

apocarpous ovary.

Simple fruits

Develop from monocarpellary or

multicarpellary syncarpous ovary.