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''Mucuna pruriens'' is a tropical legume native to Africa and tropical Asia and widely naturalized and cultivated.〔 Its English common names include velvet bean, Bengal velvet bean, Florida velvet bean, Mauritius velvet bean, Yokohama velvet bean, cowage, cowitch, lacuna bean, Lyon bean,〔(【引用サイトリンク】title=USDA GRIN Taxonomy )〕 Donkey eye, monkey tamarind, and Buffalo beans (the last also refers to ''Thermopsis rhombifolia''). The plant is notorious for the extreme itchiness it produces on contact, particularly with the young foliage and the seed pods. It has value in agricultural and horticultural use and has a range of medicinal properties. ==Description== The plant is an annual,climbing shrub with long vines that can reach over 15 m in length. When the plant is young, it is almost completely covered with fuzzy hairs, but when older, it is almost completely free of hairs. The leaves are tripinnate, ovate, reverse ovate, rhombus-shaped or widely ovate. The sides of the leaves are often heavily grooved and the tips are pointy. In young ''M.pruriens'' plants, both sides of the leaves have hairs. The stems of the leaflets are two to three millimeters long. Additional adjacent leaves are present and are about 5 mm long. The flower heads take the form of axially arrayed panicles. They are 15 to 32 cm long and have two or three, or many flowers. The accompanying leaves are about 12.5 mm long, the flower stand axes are from 2.5 to 5 mm. The bell is 7.5 to 9 mm long and silky. The sepals are longer or of the same length as the shuttles. The crown is purplish or white. The flag is 1.5 mm long. The wings are 2.5 to 3.8 cm long. In the fruit ripening stage, a 4 to 13 cm-long, 1 to 2 cm-wide, unwinged, leguminous fruit develops. There is a ridge along the length of the fruit. The husk is very hairy and carries up to seven seeds. The seeds are flattened uniform ellipsoids, 1 to 1.9 cm long, 0.8 to 1.3 cm wide and 4 to 6.5 cm thick. The ''hilum'', the base of the ''funiculus'' (connection between placenta and plant seeds) is a surrounded by a significant ''arillus'' (fleshy seed shell). ''M.pruriens'' bears white, lavender, or purple flowers. Its seed pods are about 10 cm long and are covered in loose, orange hairs that cause a severe itch if they come in contact with skin. The itch is caused by a protein known as mucunain.〔Reddy,V.B. et al. (Cowhage-evoked itch is mediated by a novel cysteine protease: a ligand of protease-activated receptors ) J. Neurosci. 28 (17), 4331-4335 (2008) PMID 18434511〕 The seeds are shiny black or brown drift seeds. The dry weight of the seeds is 55 to 85 g/100 seeds.〔 (【引用サイトリンク】title=Factsheet - Mucuna pruriens ) 〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Mucuna pruriens」の詳細全文を読む スポンサード リンク
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