Mucuna is a genus of vines and shrubs of the legume family Fabaceae: tribe Phaseoleae. It has a pan-tropical distribution and contains 112 accepted species . The genus was created in 1763 by French botanist Michel Adanson.[
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Description
Plants in this genus are mostly woody or herbaceous vines, with the exception of Mucuna stans, a shrub. The leaves are stipule and trifoliate with large leaflets. Inflorescences are produced from the or from older stems, and all except those of M. stans and Mucuna stanleyi are pendant; they may be arranged as pseudo- or pseudo-. The flowers have the characteristic pea flower form; they are large and showy and exhibit a wide range of colours across the different species. The fruit are dehiscent pods that may be ovoid or oblong and contain a number of seeds; they have divisions (septum) between each seed, the pod may be winged and/or ribbed, and they are often coated in stiff irritating hairs.
They are generally bat-pollinated and produce seeds that are buoyant . These have a characteristic three-layered appearance, appearing like the eyes of a large mammal in some species and like a hamburger in others (most notably Mucuna sloanei) and giving rise to common names like deer-eye beans, donkey-eye beans, ox-eye beans, or hamburger seed.
The name of the genus is derived from mucunã, a Tupi–Guarani word for these species.
Ecology
Some Mucuna species are used as food plants by caterpillars of Lepidoptera. These include Morpho butterflies and the two-barred flasher ( Astraptes fulgerator), which is sometimes found on Mucuna holtonii and perhaps others. The fungus Mycosphaerella mucunae is named for being first discovered on Mucuna.
Uses
The pods of some species are covered in coarse hairs that contain the protease mucunain and cause itchy blisters when they come in contact with skin; specific epithets such as pruriens (Latin: "itching") or urens (Latinized Ancient Greek: "stinging like a nettle") refer to this. Other parts of the plant have medicinal properties. The plants or their extracts are sold in herbalism against a range of conditions, such as urinary tract, neurological, and menstruation disorders, constipation, edema, , tuberculosis, and helminthiases such as elephantiasis.[Oudhia (2002)] In an experiment to test if M.pruriens might have an effect on the symptoms of Parkinson's disease, Katzenschlager et al. found that a seed powder had a comparable, if not more favourable, effect as commercial formulations of L-dopa, although the trial only consisted of four people per test group.[Katzenschlager et al. (2004)]
M. pruriens was found to increase phosphorus availability after application of rock phosphate in one Nigerian experiment.[Vanlauwe et al. (2000)] M. pruriens was used in Native American milpa agriculture.
Mucuna seeds contain a large number of Antinutrients. The most important is L-dopa, which the digestive system of most animals confuses with the amino acid tyrosine, causing the production of defective proteins. Other antinutrients are , , phytic acid, cyanogenic glycosides, and trypsin and amylase inhibitors, although all these can be removed by long cooking.[Erowid (2002): Mucuna pruriens. Created 2002-APR-22. Retrieved 2007-DEC-17] Mucuna is not traditionally consumed as a food crop, but some preliminary experiments have shown that if the antinutrients are removed or at least brought down to safe level, the beans can be fed to livestock or people. The L-dopa content is the most important and difficult toxin to get rid of. The seeds must be extensively processed before they can be safely eaten. Diallo & Berhe found the best method was to crack open the seeds and soak them in constantly running fresh water such as under an open faucet for 36 hours, or to put them in a bag and leave in a flowing river for 72 hours, before cooking them for over an hour. Over a thousand people in the Republic of Guinea were fed a meal of Mucuna (mixed with many other ingredients) with no obvious ill effects.[Diallo & Berhe (2003)]
Species
, Plants of the World Online accepts the following 112 species:
Formerly placed here
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Canavalia mattogrossensis (Barb. Rodr.) Malme (as M. mattegrossensis Barb. Rodr.)
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Psophocarpus scandens (Endl.) Verdc. (as M. comorensis Vatke)
Gallery
Flowers
File:Mucuna nigricans (9212686208).jpg| Mucuna nigricans
File:Mucuna birdwoodiana.jpg| Mucuna birdwoodiana
File:Mucuna-bennettii-SF24255-03.jpg| Mucuna bennettii with a Rainbow Lorikeet
File:Mucuna coriacea subsp. irritans 1DS-II 1-7767.jpg| Mucuna coriacea
File:大果油麻藤 Mucuna macrocarpa -香港禮賓府 Hong Kong Government House- (9252393885).jpg| Mucuna macrocarpa
Seed pods
File:Mucuna sanjappae fruit.jpg| Mucuna sanjappae
File:Mucuna poggei MS 3655.jpg| Mucuna poggei
File:Mucuna-gigantea-SF23215-02.jpg| Mucuna gigantea
File:Mucuna coriacea subsp. irritans 1DS-II 1-7770.jpg| Mucuna coriacea
File:Fruits of Mucuna membranacea.jpg| Mucuna membranacea
Further reading
External links
