The azuki bean (also spelled adzuki or aduki) is an annual vine widely grown throughout East Asia and the Himalayas for its small (approximately 5 mm) bean. The cultivars most familiar in northeast Asia have a uniform red color, but white, black, gray and variously mottled varieties are also known. Scientists presume Vigna angularis var. nippinensis is the progenitor. Genetic evidence indicates that the azuki bean was first domesticated in the Himalayas. It was cultivated in China and Korea before 1000 BC. It was later taken to Japan, where it is now the second most popular legume after the soybean.