滇桐属系统位置的分支分析

THE CLADISTIC ANALYSIS OF THE SYSTEMATIC POSITION OF CRAIGIA

本文以讨论系统位置有争议的滇桐属的归属问题,尝试在植物分类学中具体应用分支系统学原理和方法的可能性。作者认为近年来分支系统学中出现的一种倾向,即不再强调祖先和直接的谱系关系,而把分支图解仅仅作为一种归类手段,为本文提供了理论基础。通过对梧桐科和椴树科7个属15个性状状态的分支分析,建立了符合简约性原则的分支图解。分支图解表明,滇桐属与通常置于梧桐科的马克韦桐属具有较密切的关系,而它们与椴树科的关系比与梧桐科的关系更接近。结论支持把滇桐属作为椴树科成员的观点。

Making an attempt to apply the systematic methods of cladistics to plant taxonomy, the author discusses the systematic position of the genus Craigia W. W. Smith et W. E. Evans. One tendency of cladistics appeared in recent years, i. e. it do not to emphasize ancestors and direct pedigrees, only to take cladogram as a method of classification, provides theoretical basis for this paper. Seven genera, Craigia, Tilia, Mortoniodendron, Burretiodendron, Ma-xwellia, Sterculia and Reevesia selected from Tiliaccae and Stcrculiaceae are introduced as the taxa for cladistic analysis. The cladogram shows that Craigia has closest relationship with Maxwellia which is usually placed in Sterculiaceae, but both genera are more related to the members of Tiliaceae than those of Sterculiaceae.