Pisum is a genus of the family Fabaceae, native to southwest Asia and northeast Africa. It contains one to five species, depending on taxonomic interpretation; the International Legume Database (ILDIS) accepts three species, one with two subspecies [1]:
Pisum sativum (the field or garden pea), is domesticated and is a major human food crop.
Pisum species are used as food plants by the larvae of some Lepidoptera species including Bucculatrix pyrivorella, Cabbage Moth, Common Swift, Ghost Moth, Hypercompe indecisa, The Nutmeg, Setaceous Hebrew Character and Turnip Moth.
The Pisum sativum flower has 5 sepals (fused), 5 petals, 10 stamens (9 fused in a staminal tube and 1 stamen is free) and 1 subsessil carpel.
A legume /ˈlɛɡʲuːm/ 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 food grain seed (e.g. beans and lentils, or generally pulse), for livestock forage and silage, and as soil-enhancing green manure. Legumes are notable in that most of them have symbiotic nitrogen-fixing bacteria in structures called root nodules. Well-known legumes include alfalfa, clover, peas, beans, lentils, lupins, mesquite, carob, soybeans, peanuts and the woody climbing vine wisteria. Legume trees like the Locust trees (Gleditsia, Robinia) or the Kentucky coffeetree (Gymnocladus dioicus) can be used in permaculture food forests.