鹭鸶兰属的系统位置和起源

THE PHYLOGENETIC PLACE AND ORIGINATION OF THE GENUS DIURANTHERA

鹭鸶兰ＤｉｕｒａｎｔｈｅｒａＨｅｍｓｌ．为百合科的１个单种属。Ｄ。ｍｉｎｏｒＨｅｍｓｌ．特产云南、四川和贵州。其植物形态、细胞学特征和化学成分均与吊兰属Ｃｈｌｏｒｏｐｈｙｔｕｍ的北缘种西南吊兰ＣｎｅｐｅｌｅｎｓｅＢａｋｅｒ和狭叶吊兰Ｃ。ｃｈｉｎｅｎｓｅＢｕｒ．ｅｔＦｒ或大叶吊兰Ｃ。ｍａｌａｙｅｎｓｅＲｉｄｌｅｙ极为接近或一致，分布区彼此邻接或部分重叠。作者认为：泛热带属吊兰属的多倍体种如大叶吊兰Ｃｈｌｏｒｏｐｈｙｔｕｍｍａｌａｙｅｎｓｅ进入云南高原气候比较干凉的环境时发生了新的适应演化并分化出适应性不同的分支。在形态上有了突变的鹭鸶兰Ｄｉｕｒａｎｔｈｅｒａ是其分支之一，而西南吊兰和狭叶吊兰则是与鹭鸶兰平行的另一分支。该二属都是广义的百合科吊兰族Ａｓｐｈｏｄｅｌｅａｅ的成员，但Ｄｉｕｒａｎｔｈｅｒａ较为年青，大约在上新世或更新世初才出现。它的发生和发展与喜马拉雅造山运动激烈进行、云南高原较大幅度抬升、气候条件的分异息息相关，是吊兰族中的１个新生属。

Diuranthera Hemsl.is a monospecies genus of Liliaceae。D。 minor Hemsl.is endemic to Yunnan,Sichuan and Guizhou Province。Its morphological and cytological characteristics and chemical constituents are similar to or the same as the northern border species of Chlorophytum nepalense Baker and C。chinense Bur.et Fr.or C。malayense Ridley.Their distribution area are adjacent or partly overlapped.The author thinks,that the C, malayense polyploid of this pantropical genus has produced adaptable evolution and diversified into different branches when it entered into the more dry and cool Yunnan Plateau。The abruptly changed Diuran thera in mornhology is one of its branches,while the C。nepolense and C。 chinense are another parallel branch.In a broad sense,the above two genera are a member of Asphodeleae, but the Diuranthera is younger,it appeared in the Pliocene Epoch or the early Pleistocene Epoch.It is a newly emerged genus(species) of Asphodeleae the existance and development of which closely related to climate difference caused by the orogenic movement of Himalay and big rise of Yunnan plateau。