cowpea, black-eyed pea, or black-eyed bean, annual legume (Vigna sinensis) of the pulse family. Introduced in the early 18th cent. from the Old World to the S United States, it has become a staple of Southern cooking and an important catch crop, soil enhancer, and forage. Cowpea, sometimes called China bean, is grown commercially in India and China and as a high-protein subsistence crop in Africa. Cowpea is classified in the division Magnoliophyta, class Magnoliopsida, order Rosales, family Leguminosae.