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Burmanniaceae is a family of flowering plants, consisting of about a hundred species of herbaceous plants in roughly a dozen genera. Often they are quite remarkable plants, more often red than green, without much leaf area and not growing very big in any way. The reason for this appearance is that the members of the family are all myco-heterotrophic species. They are mainly distributed in the southern hemisphere and grow in shady and tropical environments. Many of the plants in the family are threatened species. The APG II system, of 2003, places the family in the order Dioscoreales, in the clade monocots. The circumscription of the family in APG II is wider than in the APG system, of 1998, and includes the plants that belonged to the family Thismiaceae in APG. However, the older classification better reflects the evolutionary relationships〔http://bio.kuleuven.be/sys/site/Publicaties/2010/Vincent%20Merckx/Monocots%202010%20Merckx.pdf〕 between the genera. The clades are as follows: Burmanniaceae ''sensu stricto'' *''Apteria'' *''Burmannia'' *''Campylosiphon'' *''Cymbocarpa'' *''Dictyostega'' *''Gymnosiphon'' *''Hexapterella'' *''Marthella'' *''Mierisella'' ''Afrothismia'' clade *''Afrothismia Tribe Thismieae * ''Haplothismia'' * ''Oxygyne'' * ''Thismia'' * ''Tiputinia'' According to molecular analyses, the myco-heterotrophic type of life that these species lead evolved six (or even more) times independently in the three clades that are part of Burmanniaceae. ''Afrothismia'' and tribe Thismieae represent two of these shifts to myco-heterotrophy from autotrophy while Burmanniaceae ''sensu stricto'' are the clade where the other four took place. The family appears in the Late Cretaceous but the further diversification and shifts to the typical habit occurred later in the same period and continued after the K-T boundary in Paleogene. ==References== 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「Burmanniaceae」の詳細全文を読む スポンサード リンク
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