Flower - Placentation

Description:

The mode of arrangement of the placentae or ovule is known as placentation.

Marginal

• Placenta forms a ridge along the ventral suture of the ovary.
• Ovules are borne on this ridge forming two rows.
• E.g. Pea.

Axile

• Placenta is axile.
• Ovules are attached to it in a multilocular ovary.
• E.g. China rose.

Parietal

• Ovules develop in the inner wall of the ovary or peripheral part.
• Ovary is one-chambered but it becomes two chambered due to the formation of a false septum.
• E.g. Mustard.

Free Central

• Ovules borne on central axis.
• Septa absent.
• E.g. Primrose.

Basal

• Placenta develops at the base of ovary.
• A single ovule is attached to it.
• E.g. Sunflower.