中国景天科山景天组的分类学研究

Sect. Oreades belongs to Sedum L. of Crassulaceae, which comprise of 67 species，and 63 species distributed in China, which is the biggest distribution and diversity center of the section. There is no comprehensive taxonomic study about this section till now, and several problems exist:Owing to the lack of systematic field investigation and population research, the taxonomic treatment is not reasonable in some taxa, and variation of many characteristics with potential taxonomic significance are poorly understood; It is difficult to treat many similar species morphologically, due to the lack of original documents and type specimens, which are difficult to obtain. All this problems result in plant taxonomic confusion and identification difficulty in this Section. This project aims to solve the up-listed problem and clarify the taxonomic relationship of this section: confirm the variation level of characters intra and inter population, and clarify the relationship between confused species by a through wild populations collection and field research; Solve difficult species through achieve original study data and type specimen photograph by online specimen database. Verify and determine the mutual relations relationship between species revealed by Geography and population studies, and confirm the relationship of species intra section through comprehensive evaluation of all taxonomic characters.

山景天组（Sect. Oreades）隶属于景天科景天属(Sedum L.)，全世界记载67种，其中我国分布63种，占总数的94%，是该组的现代分布中心。该组从建立至今，尚无系统的研究订正整理，存在以下问题：缺乏足够多的标本材料以及系统的野外调查和居群研究，对一些具有潜在分类学意义的性状认识不足，分类学处理不够合理；原始研究资料和国外模式标本获取受限，许多形态相似的种处理困难。针对上述问题，本项目拟通过以下方法，完成该组的系统分类和订正研究：进行大量的野外居群采集，观察疑难物种的成种性状在居群内和居群间的变异，解决相似种之间的关系；通过物种分类与形态地理学研究，完善本组植物的分类与地理分布；利用网络标本数据库，获取国外模式标本信息，解决疑难物种问题。通过综合性状进行表征分类学研究，验证和判定基于形态地理和居群研究所揭示出的相互关系并建立组下分类系统。