Placement

What is placentation? This is the arrangement of the ovules in an ovary.

Marginal placentation:

The placenta appears as one ridge on the ovary wall e.g. bean.

Parietal placentation:

The placenta is on the ridges on ovary wall. Ovules are in them e.g. pawpaw.

Axile placentation:

The placenta is in the centre. Ovary is divided into a number of loculi. e.g. orange.

Basal placentation.

The placenta is formed at the base of the ovary e.g. sunflower.

Free Central placentation.

Placenta is in the centre of the ovary. There are no loculi e.g. in primrose.