Legume
A legume ( or ) is a plant in the family Fabaceae (or Leguminosae), or the fruit or seed of such a plant. Legumes are grown agriculturally, primarily for their grain seed called pulse, for livestock forage and silage, and as soil-enhancing green manure. Well-known legumes include alfalfa, clover, peas, beans, lentils, lupins, mesquite, carob, soybeans, peanuts and tamarind.
A legume fruit is a simple dry fruit that develops from a simple carpel and usually dehisces (opens along a seam) on two sides. A common name for this type of fruit is a pod, although the term "pod" is also applied to a few other fruit types, such as that of vanilla (a capsule) and of radish (a silique).
Legumes are notable in that most of them have symbiotic nitrogen-fixing bacteria in structures called root nodules. For that reason, they play a key role in crop rotation.
Terminology
The term "pulse", as used by the United Nations' Food and Agricultural Organization (FAO), is reserved for crops harvested solely for the dry seed. This excludes green beans and green peas, which are considered vegetable crops. Also excluded are crops that are mainly grown for oil extraction (oilseeds like soybeans and peanuts), and crops which are used exclusively for sowing (clovers, alfalfa). However, in common use, these distinctions are not clearly made, and many of the varieties so classified are also used as vegetables, with their beans in pods while young; cooked in whole cuisines; and sold for the purpose; for example, black-eyed beans, lima beans and Toor or pigeon peas are thus eaten as fresh green beans, or cooked as part of a meal.
