A 'legume' is a
plant in the family
Fabaceae (or Leguminosae), or a
fruit of these plants. A 'legume' fruit is a
simple dry fruit which 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 pod is also applied to a few other fruit types. Well-known legumes include
alfalfa,
clover,
peas,
beans,
lentils,
lupins and
peanuts. A peanut is not a
nut in the botanical sense; a peanut is an
indehiscent legume, that is, one whose pod does not split open on its own.

Varieties of soybean seeds, a popular legume

Pea pods
The
history of legumes is tied in closely with that of human civilization, appearing early in
Asia, the
Americas (the
common bean, several varieties) and
Europe (broad beans) by 6,000
BC, where they became a staple, essential for supplementing protein where there was not enough meat.
Legume plants are noteworthy for their ability to
fix atmospheric nitrogen, an accomplishment attributable to a
symbiotic relationship with certain bacteria known as
rhizobia found in
root nodules of these plants. The ability to form this symbiosis reduces
fertilizer costs for farmers and gardeners who grow legumes, and means that legumes can be used in a
crop rotation to replenish soil that has been depleted of
nitrogen.
Legume seed and foliage has a comparatively higher
protein content than non-legume material, probably due to the additional nitrogen that legumes receive through nitrogen-fixation symbiosis. This high protein content makes them desirable crops in
agriculture.
Farmed legumes can belong to numerous classes including
forage,
grain, blooms, pharmaceutical/industrial, fallow/green manure and timber species, with most commercially farmed species filling two or more roles simultaneously.
★ Forage legumes are of two broad types. Some, like
alfalfa,
clover,
vetch, stylo or
Arachis, are sown in
pasture and grazed by livestock. Other forage legumes such as
Leucaena or
Albizia are woody shrub or tree species that are either broken down by livestock or regularly cut by humans to provide stock feed.
★ Grain legumes are cultivated for their
seeds, and are also called
pulses. The seeds are used for human and animal consumption or for the production of oils for industrial uses. Grain legumes include
beans,
lentils,
lupins,
peas and
peanuts.
[1]
★ Bloom legume species include species such as
lupin which are farmed commercially for their blooms as well as being popular in gardens worldwide.
★ Industrial farmed legumes include
Indigofera and
Acacia species which are cultivated for dye and food gum production respectively.
★ Fallow/green manure legume species are cultivated to be tilled back into the soil in order exploit the high nitrogen levels found in most legumes. Numerous legumes are farmed for this purpose including
Leucaena, Cyamopsis and
Sesbania species.
★ Various legume species are farmed for timber production worldwide including numerous
Acacia species, Erythroxylum species and
Castanospermum australe.
The term is derived from the
French word "légume" which, however, has a wider meaning and refers to any kind of
vegetable; the English word legume being translated in French by the word légumineuse.
Legumes are a good source of
iron and
fiber.
References
1. The gene bank and breeding of grain legumes (lupine, vetch, soya and beah) / B.S. Kurlovich and S.I. Repyev (Eds.), - St. Petersburg, The N.I. Vavilov Institute of Plant Industry, 1995, 438p. - (Theoretical basis of plant breeding. V.111)
See also
★
Pulse (legume)
External links
★
AEP - European association for grain legume research
★
Lupins - Geography, classification, genetic resources and breeding
★
ILDIS - International Legume Database & Information Service
★
Legume classes from LegumeChef.com