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''Calotropis'' is a genus of flowering plants in the dogbane family, Apocynaceae, first described as a genus in 1810. It is native to southern Asia and North Africa.〔(Flora of China Vol. 16 Page 202 牛角瓜属 niu jiao gua shu ''Calotropis'' R. Brown, Mem. Wern. Nat. Hist. Soc. 1: 39. 1810 )〕 They are commonly known as milkweeds because of the latex they produce. ''Calotropis'' species are considered common weeds in some parts of the world. The flowers are fragrant and are often used in making floral tassels in some mainland Southeast Asian cultures. Fibers of these plants are called madar or mader. ''Calotropis'' species are usually found in abandoned farmland. ==Botanical description== ''Calotropis gigantea'' and ''C. procera'' are the two most common species in the genus. ''Calotropis gigantea'' grows to a height of while ''C. procera'' grows to about . The leaves are sessile and sub-sessile, opposite, ovate, cordate at the base. The flowers are about in size, with umbellate lateral cymes and are colored white to pink and are fragrant in case of ''C. procera'' while the flowers of ''C. gigantea'' are without any fragrance and are white to purple colored, but in rarer cases are also light green-yellow or white. The seeds are compressed, broadly ovoid, with a tufted micropylar coma of long silky hair.〔http://www.hort.purdue.edu/newcrop/CropFactSheets/calotropis.html〕 Pollination is performed by bees (entomophily) by the following mechanism: The stigmas and androeciums are fused to form a gynostegium. The pollen are enclosed in pollinia (a coherent mass of pollen grains). The pollinia are attached to an adhesive glandular disc at the stigmatic angle. When a bee lands on one of these, the disc adheres to its legs, and the pollinium is detached from the flower when the bee flies away. When the bee visits another flower, the flower is pollinated by the adhering pollinium on the bee. ;Species〔(The Plant List, genus ''Calotropis'' )〕 # ''Calotropis acia'' Buch.-Ham. - India # ''Calotropis gigantea'' (L.) Dryand. - China, Indian Subcontinent, Southeast Asia # ''Calotropis procera'' (Aiton) Dryand. - China, Indian Subcontinent, Southeast Asia, Middle East, North Africa ;formerly included〔 ''Calotropis sussuela'', syn of ''Hoya imperialis'' 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「Calotropis」の詳細全文を読む スポンサード リンク
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