Any of several leguminous plants, or their seeds, long utilized as food by humans or livestock. Some 14 genera of the legume family contain species producing seeds termed “beans” which are useful to humans. Twenty-eight species in 7 genera produce beans of commercial importance, which implies that the bean can be found in trade at the village level or up to and including transoceanic commerce.
The principal Asiatic beans include the edible soybeans, Glycine sp., and several species of the genus Vigna, such as the cowpea and mung, grams, rice, and adzuki beans. The broad bean (Vicia faba) is found in Europe, the Middle East, and Mediterranean region, including the North African fringe. Farther south in Africa occur Phaseolus beans, of the vulgaris (common bean) and coccineus (scarlet runner) species. Some Phaseolus beans occur in Europe also. The cowpea, used as a dry bean, is also found abundantly in Nigeria.
In the Americas, the Phaseolus beans, P. vulgaris and P. lunatus (lima bean), are the principal edible beans, although the blackeye cowpea, mung bean, and chick pea or garbanzo (Cicer arietinum) are grown to some extent. Phaseolus coccineus is often grown in higher elevations in Central and South America, as is Vicia faba. The tepary bean (P. acutifolius) is found in the drier southwestern United States and northern Mexico.
Bean plants may be either bush or vining types, with white, yellow, red, or purple flowers. The seed itself is the most differentiating characteristic of bean plants. It may be white, yellow, black, red, tan, cream-colored, or mottled, and range in weight from 0.0044 to over 0.025 oz (125 to over 700 mg) per seed. Seeds are grown in straight or curved pods (fruit), with 2–3 seeds per pod in Glycine to 18–20 in some Vigna.
Beans are consumed as food in several forms. Lima beans and snap beans are used as fresh vegetables, or they may be processed by canning or freezing. Limas are also used as a dry bean. Mung beans are utilized as sprouts. Usage of dry beans (P. vulgaris) for food is highly dependent upon seed size, shape, color, and flavor characteristics, and is often associated with particular social or ethnic groups.
the fruit of the plants of the order Leguminosae, formed from the elevated ovaries of single carpels. It is usually a dry fruit, opening from top to bottom by two pulses (peas, French beans, vetch, and others). The beans of some varieties (such as sweet clover and clover) do not open. The beans of the peanut ripen in the soil and do not crack. The beans of the “horn of Tsargrad” (Ceratonia siliqua) are succulent and sweet. The bean usually contains several seeds, fastened to the peritoneal joint by short placentas. The size, shape, and structure of beans vary—in most types the bean is straight, more or less planar (for example, peas and French beans); in others they are round, bent, or twisted into spirals (common alfalfa). Some varieties of beans break into one-seed parts. The pulses of wild varieties of beans twist up suddenly and scatter their seeds. The leguminous seeds are called beans by laymen, and the beans themselves are called pods. This is incorrect, as the pod has different markings and is characteristic of the Cruciferae family.