Piptadenia (Leguminosae, Mimosoideae) in the state of Minas Gerais, Brazil

Abstract The genus Piptadenia includes approximately 24 species that are distributed in the tropical regions of South America, with centers of diversity in the Amazon and Atlantic Forest in Brazil in which twenty-one species occur. A taxonomic study of Piptadenia was conducted in the state of Minas Gerais based on an analysis of approximately 270 specimens from 11 herbaria, field observations and field work in the main conservation units and other focal areas in Minas Gerais. These areas include the three vegetation domains in the state: Atlantic Forest, Cerrado and Caatinga. Six of the species in the genus were sampled: P. adiantoides, P. gonoacantha, P. macradenia, P. micracantha, P. paniculata and P. viridiflora. Two species that have previously been cited in the state were not found in this study: P. irwinii and P. stipulacea. These species were not found in the herbaria collections that were consulted or during the field work. We present an identification key for the Minas Gerais species of Piptadenia as well as descriptions, illustrations, geographical distributions, comments about the taxonomic characters and some information related to the flowering and fruiting periods.

摘要：相思树属（Piptadenia）共计约24个物种，分布于南美洲热带区域，其物种多样性中心位于巴西的亚马逊雨林与大西洋森林，该区域内分布有该属21个物种。本研究针对巴西米纳斯吉拉斯州的相思树属开展分类学研究，基于对11个标本馆的约270份标本的分析，以及在该州主要保护单元与其他重点区域开展的野外观察与实地考察。本次研究覆盖该州三大植被域：大西洋森林、塞拉多（Cerrado）与卡廷加（Caatinga）。本研究共采集到该属6个物种：扁叶相思树（Piptadenia adiantoides）、刺果相思树（Piptadenia gonoacantha）、大腺相思树（Piptadenia macradenia）、小刺相思树（Piptadenia micracantha）、圆锥相思树（Piptadenia paniculata）与绿花相思树（Piptadenia viridiflora）。此前有文献记载该州分布有另外2个物种，但本研究未发现：Piptadenia irwinii与Piptadenia stipulacea。在本次查阅的标本馆馆藏标本及野外考察过程中，均未采集到这两个物种。本研究提供了米纳斯吉拉斯州相思树属物种的分类检索表，同时包含各物种的形态描述、插图、地理分布信息、分类学特征评述，以及部分与开花和结果期相关的研究资料。