Carpel

Carpel (Gr. karpos, 'fruit'), in Botany, a modified leaf forming the whole or part of the gynoecium or female (ovule-bearing) organ or organs of a flower (see FLOWER). The number of carpellary leaves may vary greatly; at first indefinite in the simplest flowers (e.g. Ranunculaceæ), it becomes definite, and may even be reduced to one (e.g. Leguminosæ, Berberidaceæ). The carpellary leaves may also unite more or less completely to form a compound ovary with or without united styles or stigmas. This is characteristically three-celled in most monocotyledons (e.g. Liliaceæ), and five or two celled in the majority of dicotyledonous orders. The carpellary leaves like any others are in their simplest forms at first individually developed, and are clearly recognisable as reduced foliage leaves in Cycadaceæ. In Coniferæ (Gymnosperms) they are still further reduced, while in monocotyledons and dicotyledons (Angiosperms) they never fully open as leaves at all, save sometimes in the splitting of the fruit after maturity. For their relation to the ovule, see OVULE, REPRODUCTION, SEED.