allendospermo

Allendospermo is a botanical term used to describe seeds in which the endosperm remains as a distinct tissue at seed maturity. The endosperm is a triploid tissue formed inside the seed after double fertilization and serves as a nutritive reserve for the developing embryo during germination.

In allendospermic seeds, the endosperm often fills a large part of the seed cavity and constitutes a major portion of the edible grain in many species. This contrasts with exalbuminous seeds, in which the endosperm is consumed by the developing embryo or is reduced to a negligible amount, leaving the cotyledons as the primary storage organs. Thus, allendospermo describes seeds where the endosperm persists, while exalbuminous describes seeds where it does not.

Common examples of allendospermic seeds are those of many cereals, such as maize, wheat, and rice, where the endosperm forms the starchy portion of the grain used in milling and human consumption. Outside of cereals, the degree of endosperm persistence varies among plant groups, and in some lineages the endosperm becomes small or disappears by maturity.

The presence or absence of endosperm at maturity has implications for seed physiology, storage, and agricultural use. Endosperm provides starches and other reserves that support seedling growth and can influence germination vigor and seed handling.

See also: endosperm, albuminous seeds, exalbuminous seeds, seed physiology.