Legume Information

A legume (pronounced /ˈlɛɡ(j)uːm/) in botanical writing is a plant in the family Fabaceae (or Leguminosae), or a fruit of these specific plants. 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 vanilla and radish. Well-known legumes include alfalfa, clover, peas, beans, lentils, lupins, mesquite, carob, soy, and peanuts. Locust trees (Gleditsia or Robinia), wisteria, and the Kentucky coffeetree (Gymnocladus dioicus) are also legumes.^[1]

History

The term legume is derived from the Latin word legumen (with the same meaning as the English term), which is in turn believed to come from the verb legere which means "to gather." English borrowed the term from the French "légume," which, however, has a wider meaning in the modern language and refers to any kind of vegetable; the English word legume being translated in French by the word légumineuse.

The history of legumes is tied in closely with that of human civilization, appearing early in Asia, the Americas (the common Phaseolus bean in several varieties), and Europe (broad beans), where they became a staple, essential for supplementing protein where meat was less available.

Fixation of nitrogen in the soil

Legume plants are notable for their ability to fix atmospheric nitrogen, thanks to a symbiotic relationship with bacteria (rhizobia) found in root nodules of these plants. The ability to form this mutualism reduces fertilizer costs for farmers and gardeners who grow legumes, and allows legumes to be used in a crop rotation to replenish soil that has been depleted of nitrogen. The nitrogen fixation ability of legumes is enhanced by the availability of calcium in the soil and reduced by the presence of ample nitrogen.

Legume seed and foliage have a comparatively higher protein content than non-legume material, probably due to the additional nitrogen that legumes receive through nitrogen-fixation symbiosis. The high protein content makes them desirable crops in agriculture.

Uses by humans

Farmed legumes can belong to many agricultural classes, including forage, grain, blooms, pharmaceutical/industrial, fallow/green manure, and timber species. Most commercially farmed species fill two or more roles simultaneously, depending upon their degree of maturity when harvested.

Forage legumes are of two broad types. Some, like alfalfa, clover, vetch (Vicia), stylo (Stylosanthes), 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 livestock 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.^[2]

Legume species grown for their flowers include lupins, which are farmed commercially for their blooms as well as being popular in gardens worldwide.

Nutritional facts

Legumes contain relatively low quantities of the essential amino acid methionine - however, this should not be a problem if an adequate amount of protein is consumed.

According to the protein combining theory, legumes should be combined with another protein source such as a grain in the same meal, to balance out the amino acid levels. Protein combining has lost favor as as theory (with even its original proponent, Frances Moore Lappé, rejecting the need for protein combining in 1981^[3]) - a variety of protein sources is considered healthy, but these do not have to be consumed at the same meal. In any case, vegetarian cultures often serve legumes along with grains, which are low in the essential amino acid lysine, creating a more complete protein than either the beans or the grains on their own.

Common examples of such combinations are dal with rice by Indians, and beans with corn tortillas, tofu with rice, and peanut butter with wheat bread.^[4]

References

1. ^ Cirrus Digital: Tree Encyclopedia
2. ^ The gene bank and breeding of grain legumes (lupine, vetch, soya, and beah) , B.S. Kurlovich and S.I. Repyev (eds.), St. Petersburg:N.I. Vavilov Institute of Plant Industry, 1995, 438p. - (Theoretical basis of plant breeding. V.111)
3. ^ Diet for a Small Planet (ISBN 0-345-32120-0), 1981, p. 162; emphasis in original
4. ^ Vogel, Steven. Prime Mover – A Natural History of Muscle. W. W. Norton & Company, Inc., USA (2003), p. 301. ISBN 039332463X; ISBN 978-0393324631. in Google books

External links

Media related to Legumes at Wikimedia Commons

• AEP - European association for grain legume research
• Lupins - Geography, classification, genetic resources and breeding
• ILDIS - International Legume Database & Information Service
• Bioversity International The significance of Vavilov’s scientific expeditions and ideas for development and use of legume genetic resources
• Legume Futures A major research initiative to develop novel uses for legumes in environmentally and economically sustainable cropping.

Categories:

• Legumes
• Fruit morphology
• Vegan cuisine
• Vegetarian cuisine

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