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''Zamia'' is a genus of cycad of the family Zamiaceae, native to Mexico, the West Indies,and Central and South America as far south as Bolivia.〔(Kew World Checklist of Selected Plant Families )〕〔Hill, K.D. & Stevenson, D.W. (1999). A world list of Cycads, 1999. Excelsa 19: 67-72.〕 The range of one species (''Z. integrifolia'',extends into the contiguous United States, i.e. Georgia and Florida.〔(Flora of North America, vol 2, ''Zamia integrifolia'' Linnaeus f. in Aiton, Hort. Kew. 3: 478. 1789. )〕〔Standley, P. C. & J. A. Steyermark. 1958. Cycadaceae. In Standley, P.C. & Steyermark, J.A. (Eds), Flora of Guatemala - Part I. Fieldiana, Bot. 24(1): 11–20. 〕 The genus comprises deciduous shrubs with aerial or subterranean circular stems, often superficially resembling palms. They produce spirally arranged, pinnate leaves which are pubescent, at least when young, having branched and simple, transparent and coloured hairs. The articulated leaflets lack a midrib, and are broad with subparallel dichotomous venation. Lower leaflets are not reduced to spines, though the petioles often have prickles. The emerging leaves of many ''Zamia'' species are striking, some emerging with a reddish or bronze cast (''Z. roesli'' is an example). ''Zamia picta'' is even more distinctive, being the only truly variegated cycad (having whitish/yellow speckles on the leaves).〔Nicolalde-Morejón, F., A. P. Vovides & D. W. Stevenson. 2009. Taxonomic revision of Zamia in Mega-Mexico. Brittonia 61(4): 301–335.〕 ''Zamia'' sporophylls are born in vertical rows in cones, and the megasporophyll apices are faceted or flattened, not spinose. The fleshy seeds are subglobular to oblong or ellipsoidal, and are red, orange, yellow or rarely white. The endosperm is haploid, derived from the female gametophyte. The embryo is straight, with two cotyledons that are usually united at the tips and a very long, spirally twisted suspensor. The sperm of the genus are large, as is typical of cycads, and ''Zamia roezlii'' is an example; its sperm are approximately 0.4 mm long and can be seen by the unaided eye. All the species of ''Zamia'' produce leafy crowns of foliage that make them choice garden specimens and most varieties branch heavily in age to produce handsome clumps. With a few exceptions, most ''Zamia'' species are found in warm, humid, tropical rainforest habitats, growing in the forest understory. However, many species are still fairly adaptable, performing quite well in cultivation, especially in subtropical areas. All species need good drainage and protection from the cold. At least one species, ''Z. pseudoparasitica'', grows as an epiphyte in the branches of trees. The name ''Zamia'' comes from the Greek ''azaniae'', meaning "a pine cone". == Species == Accepted species:〔 # ''Zamia acuminata'' Oerst.ex Dyer (Costa Rica # ''Zamia amazonum'' D.W.Stev. - Venezuela, Colombia, Ecuador, Peru, Brazil # ''Zamia amplifolia'' Hort.Bull ex Mast. - Colombia # ''Zamia angustifolia'' Jacq. - The Bahamas, Cuba # ''Zamia boliviana'' (Brongn.) A.DC. - Bolivia, Mato Grosso # ''Zamia chigua'' Seem. - Colombia # ''Zamia cremnophila'' Vovides, Schutzman & Dehgan - Tabasco # ''Zamia cunaria'' Dressler & D.W.Stev. - Panama # ''Zamia decumbens'' Calonje, Meerman, M.P. Griff. & Hoese - Belize # ''Zamia disodon'' D.W.Stev. & Sabato - Colombia # ''Zamia dressleri'' D.W.Stev. - Panama #''Zamia elegantissima'' Schutzman, Vovides & R.S.Adams - Panama # ''Zamia encephalartoides'' D.W. Stev. (Colombia) #''Zamia erosa'' O.F.Cook & G.N.Collins - Cuba, Jamaica, Puerto Rico # ''Zamia fairchildiana'' L.D.Gómez - Panama, Costa Rica # ''Zamia fischeri'' Miq. ex Lem. - 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「Zamia」の詳細全文を読む スポンサード リンク
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