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''Bifrenaria'', abbreviated Bif. in horticultural trade, is a genus of plant in family Orchidaceae. It contains 20 species found in Panama, Trinidad and South America. There are no known uses for them, but their abundant, and at first glance artificial, flowers, make them favorites of orchid growers. The genus can be split in two clearly distinct groups:〔Cogniaux, Celestin A.(1902). ''Bifrenaria'' in Flora Brasiliensis K.F.P.von Martius & auct. suc. (eds.) vol.3 p. 5: 476. (published on Internet. )〕 one of highly robust plants with large flowers, that encompass the first species to be classified under the genus ''Bifrenaria''; other of more delicate plants with smaller flowers occasionally classified as ''Stenocoryne'' or ''Adipe''. There are two additional species that are normally classified as ''Bifrenaria'', but which molecular analysis indicate to belong to different orchid groups entirely. One is ''Bifrenaria grandis'' which is endemic to Bolívia and which is now placed in ''Lacaena'',〔Kraenzlin, Friedrich Wilhelm Ludwig (1928). While ''Lacaena grandis'' in Repertorium specierum novarum regni vegetabilis. Ed. Selbstverlag des Herausgebers, Berlin, at vol.25: 25.〕 and ''Bifrenaria steyermarkii'', an inhabitant of the northern Amazon Forest,〔Dunsterville, Galfried Clement Keyworth & Garay, Leslie A. (1976). ''Bifrenaria steyermarkii'' in Venezuelan Orchids Illustrated vol.6: 56. London.〕 which does not have an alternative classification. ==Description== ''Bifrenaria'' are generally robust plants, of sympodial growth, between ten and sixty centimeters tall. They are characterized by round-section root with thick velamen, four-angled fleshy pseudobulbs of one internode, often basally protected by dried sheaths and with only one apical leaf(except for ''Bifrenaria steyermarkii'', which occasionally has two),〔Foldats, Ernesto (1970). ''Xylobium steyermarkii'' em Novedades Cientificas, Contribuciones Occasionales del Museo de Historia Natural La Salle vol.35: 1. Serie Botanica. Caracas.〕 plicate (fan-folded) enervated leathery leaves, yet malleable and not exceedingly thick, with a pseudo-petiole of basal round section, and a basal inflorescences bearing up to ten flowers, which seldom surpass the leaves' length.〔 ''Bifrenaria'' flowers are strongly scented, they have sepals slightly larger than the petals, with the lateral ones basally united to the column foot forming a calcar with truncated extremity.The column is slightly arching, generally without wings or any other appendages, bearing a foot which the labellum is hinged to, whose shape varies, articulated to the column, with a longitudinal channeled callus often with a basal claw. Flowers show two elongated stipes, hardy ever one, at least twice longer than wide, with salient viscidium, visible caudicles and retinacle in inverted positions. The superposed pollinia number four, and are protected by a deciduous incumbent anther.〔 Fruits are green, erect or pendulous; they take about eight months to ripe and hold hundreds of thousand yellowish or brownish elongated seeds up to 0.35 mm long.〔Dressler, Robert L. (1993). Phylogeny and classification of the orchid family. Cambridge University Press.〕 Among all the mentioned, the main characteristic distinguishing ''Bifrenaria'' from its closest relatives is the presence of the calcar.〔Frederico C. Hoehne (1953). ''Bifrenaria'' in Flora Brasílica, Vol 12, 7. Instituto de Botânica de São Paulo.〕 Other important characters are the four-sided single-leaved pseudobulbs besides the raceme inflorescence with two to ten flowers.〔Campacci, Marcos A. (2003). Coletânea de Orquídeas Brasileiras II, ''Bifrenaria''. Ed. Brasil Orquídeas. 〕 Little is known about pollination in ''Bifrenaria''. Apparently the only existing records report the presence of some large species' pollinia observed on the back of male ''Eufriesea violacea'' bees (Euglossinae),〔Dressler, Robert L. (1990). The orchids natural history and classification. London: Harvard University Press.〕 and of ''Bombus brasiliensis'' (Bombini).〔Singer, Rodrigo B. & Koehler, S. (2004). Pollinarium morphology and floral rewards in Brazilian Maxillariinae (Orchidaceae). Annals of Botany 93: 39–51.〕 Although there are no reports of flower pollination being directly observed, a paper published in 2006 studied the micromorphology of the labellum in ''Bifrenaria'' species, looking for substances useful to insects as food.〔Davies, K.L. & Stpiczynska, M. (2006). Labellar Micromorphology of Bifrenariinae Dressler (Orchidaceae). Annals of Botany Company. Oxford University Press. (published on the Internet )〕 The absence of such substances on the densely pubescent surface of most ''Bifrenaria'' labelli seems to indicate possible pollination by large bees as the major mean. Another indicator of this possibility is the strong smell emanated by species like ''B. tetragona'' which are similar to those of plants in other families which are also pollinated by these bees. The smaller pubescent species may be pollinated by smaller bees, while the smooth ones, which have strong colored flowers, as ''B. aureofulva'', might be pollinated by hummingbirds.〔 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「Bifrenaria」の詳細全文を読む スポンサード リンク
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