A pulse (Latin "puls", from Greek " " - poltos, "porridge") is an annual leguminous crop yielding from one to twelve seeds of variable size, shape, and color within a pod. Pulses are used for food and animal feed. The term "pulse", as used by the 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 and 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 cooked as part of a meal. Pulses are important food crops due to their ability to fix nitrogen. Just like words such as "bean" and "lentil", the word "pulse" may also refer to just the seed, rather than the entire plant.