Placentation - Types

Biology

definition

Placentation

Placentation is the arrangement of ovules in the ovary of a plant. The given diagram shows the types of placentation such as basal, apical, parietal, marginal, axial, and free central.

1. Marginal: One elongated palcenta is located on one side of ovary. Ovules are attached at the line of carpel's margin e.g., Legumes.
2. Axil: Carpels are folded inward with ovules placed along the central axis of ovary e.g., tomato.
3. Parietal: Ovules develop on the inner wall of the ovary e.g., Poppy.
4. Free-central: Ovule develop on the central axis while the septa is absent e.g., Dianthus.
5. Basal: The ovules are arranged at the base of the ovary e.g., sunflower.
6. Superficial: Ovules are attached entirely to the inner surface of the ovary e.g. Nymphea.