Placentation is the arrangement of the ovules in the ovary and their attachment to it. Placentation are of various type in the angiosperms - marginal, axile, central, parietal, basal, and free central.

In marginal placentation, ovules are attached to the ridge formed on the ventral suture of the ovary without any locules. Pea plant has this arrangement. When the ovules are attached to the central column and the ovary wall forms chambers called locules separating the ovules from each other is said the axile placentation. In parietal, the ovules are attached to the inner wall or towards the periphery of the ovary. In basal placentation the ovules are attached at the base of the ovary with single locus or chamber. Free-central placentation is when the ovules are attached at the central axis of the ovary without any septa present like in axile pattern.