Parietal placentation

Parietal Placentation is a type of placentation found in angiosperms, or flowering plants. It is characterized by the development of ovules along the outer walls of the ovary, rather than on a central axis as in other types of placentation.

Overview

In parietal placentation, the ovules are attached to the periphery of the ovary, on what is known as the placenta. This placenta is formed from the fusion of the ovary wall and the carpel, the female reproductive organ of the flower. The ovules develop into seeds after fertilization, and the ovary develops into the fruit.

Occurrence

Parietal placentation is found in a number of plant families, including the Brassicaceae, Cactaceae, and Papaveraceae. It is also common in the Ranunculaceae, or buttercup family, and the Violaceae, or violet family.

Comparison with Other Types of Placentation

Parietal placentation differs from other types of placentation in the location of the ovules. In axile placentation, for example, the ovules are attached to a central column in the ovary. In basal placentation, the ovules are attached at the base of the ovary. In free central placentation, the ovules are attached to a free-standing column in the center of the ovary.

See Also

• Placentation
• Ovary (botany)
• Ovule
• Fertilization
• Seed
• Fruit
• Carpel
• Placenta (botany)