Type of Placentation

Description with example

Diagram

Marginal

There is a single placenta which develop along the junction of two fused margins, e.g, pea.

Axile

Mutlicarpellary, syncarpous gynoecium inward growth of carpel's margin forms a multicarpellary condition that contains an axis in the centre. Placenta arises from central axis bearing ovules.

e.g., Solanum, Chinarose.

Parietal

The number of placenta corresponds to number of fusing carpels. Sometimes the ovules bearing placenta grow inward to form false septa and thus ovary becomes bilocular (e.g, mustard) and trilocular

e.g., Curcurbita

Free central

The ovary is unilocular and ovules are borne on the central-axis and not connected to the Ovary wall by septum.

e.g., Dianthus, Silensa.

Basal

The ovary is unilocular and the single ovule is borne at the base of the ovary attached by a single placenta,

e.g., sunflower, wheat.