Department of Organismic and Evolutionary Biology, Harvard University Herbaria, 22 Divinity Avenue, Cambridge, Massachusetts 02138 USA.
Am J Bot. 2002 Feb;89(2):312-26. doi: 10.3732/ajb.89.2.312.
Cacti are a large and diverse group of stem succulents predominantly occurring in warm and arid North and South America. Chloroplast DNA sequences of the trnK intron, including the matK gene, were sequenced for 70 ingroup taxa and two outgroups from the Portulacaceae. In order to improve resolution in three major groups of Cactoideae, trnL-trnF sequences from members of these clades were added to a combined analysis. The three exemplars of Pereskia did not form a monophyletic group but a basal grade. The well-supported subfamilies Cactoideae and Opuntioideae and the genus Maihuenia formed a weakly supported clade sister to Pereskia. The parsimony analysis supported a sister group relationship of Maihuenia and Opuntioideae, although the likelihood analysis did not. Blossfeldia, a monotypic genus of morphologically modified and ecologically specialized cacti, was identified as the sister group to all other Cactoideae. The tribe Cacteae was found to be sister to a largely unresolved clade comprising the genera Calymmanthium, Copiapoa, and Frailea, as well as two large and well-supported clades. Browningia sensu stricto (excluding Castellanosia), the two tribes Cereeae and Trichocereeae, and parts of the tribes Notocacteae and Rhipsalideae formed one clade. The distribution of this group is largely restricted to South America. The other clade consists of the columnar cacti of Notocacteae, various genera of Browningieae, Echinocereeae, and Leptocereeae, the tribes Hylocereeae and Pachycereeae, and Pfeiffera. A large portion of this latter group occurs in Central and North America and the Caribbean.
仙人掌是一个庞大而多样化的茎肉质植物群，主要分布在温暖和干旱的北美和南美。为了提高在三个主要的仙人掌类群中的分辨率，从这些类群的成员中加入了 trnL-trnF 序列到一个综合分析中。三个佩雷斯凯亚的范例没有形成一个单系群，而是一个基础等级。支持良好的仙人掌亚科和仙人球亚科以及 Maihuenia 属形成了一个与佩雷斯凯亚弱支持的分支。简约分析支持 Maihuenia 和仙人球亚科的姊妹群关系，尽管似然分析没有。布洛斯菲迪亚，一个形态上修饰和生态上特化的仙人掌单种属，被确定为所有其他仙人掌类群的姊妹群。仙人掌族被发现与一个基本上未解决的分支形成姊妹群，该分支包括 Calymmanthium、Copiapoa 和 Frailea 属，以及两个大的和支持良好的分支。布朗宁尼亚属（不包括卡斯特兰西亚属）、两个 Cereeae 族和 Trichocereeae 族，以及部分 Notocacteae 和 Rhipsalideae 族形成一个分支。这个群体的分布主要局限于南美洲。另一个分支由 Notocacteae 的柱状仙人掌、各种 Browningieae、Echinocereeae 和 Leptocereeae 属、Hylocereeae 和 Pachycereeae 族以及 Pfeiffera 组成。后者的大部分分布在中美洲、北美洲和加勒比地区。
