Gynoecium (G):

It is the female reproductive part of flower and innermost in position.

It is also known as pistil.

The individual member of gynoecium is known as carpel.

The number of carpels may be one to many.

If all the carpels are fused the condition is described as syncarpous and if they are free the condition is described as apocarpous.

The polycarpellary gynoecium can be bicarpellary (two carpels e.g. Datura) tricarpellary (three carpels e.g. Cucurbita), pentacarpellery (five carpels e.g. Hibiscus) and so on.

A typical carpel consists of three parts stigma, style and ovary.

Stigma is a terminal part of carpel which receives pollen grains during pollination. It helps in germination of pollen grain.

Stigma shows variation in structure to suit the pollinating agent.

Style is narrow thread like structure that connects ovary with stigma.

Ovary is basal swollen fertile part of the carpel.

Ovules are produced in ovary on a soft fertile tissue called placenta.

Placentation :

The mode of arrangement of ovules on the placenta within the ovary is placentation.

Types of Placentation :

Marginal :

Ovules are placed on the fused margins of unilocular ovary, e.g. Pea, Bean etc.

Axile :

Ovules are placed on the central axis of a multilocular ovary, e.g. Chinarose, Cotton; etc

Parietal:

Ovules are placed on the inner wall of unilocular ovary of multicarpellary syncarpus gynoecium. e.g. Papaya, Cucumber,

Basal :

Single ovule is present at the base of unilocular inferior ovary, e.g. Sunflower, Rice, Wheat.

Free central:

Ovules are borne on central axis which is not attached to ovary wall. e.g. Fig.