We analyzed patterns of morphological differentiation of the Habenaria parviflora complex (Orchidaceae), through morphometric analyses of populations and morphotypes, aiming at evaluating current taxonomic proposals and at identifying discriminative characters for the delimitation of taxa. We performed multivariate and univariate morphometric analyses using 18 morphological characters of 675 individuals from 65 populations distributed throughout Brazil, Argentina and Uruguay, representing 12 morphotypes that comprise nearly all the morphological diversity and geographic distribution of the complex. The group presents morphological patterns difficult to understand which suggest that the complex does not correspond to a single species, nor does each morphotype correspond to a taxon. It was possible to clearly differentiate only two taxa, apart from H. parviflora, by a combination of characters: H. paulensis and H. ulei. Characters associated with flower size, leaf width and opening angle of the sepals were the most discriminatory for both species. The relationships between the populations of the remaining morphotypes exhibited high overlap in the analyses, making it impossible to define morphological groups with the characters used. The number of flowers, ovary length and angles between floral structures, not previously used in the taxonomy of this complex, are important characters for the recognition of taxa and can be further explored by future taxonomic studies of both the group and the genus.

中文翻译：

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Habenaria parviflora 复合体（兰科）的形态计量学分析

我们通过种群和形态类型的形态测量分析分析了 Habenaria parviflora 复合体（兰科）的形态分化模式，旨在评估当前的分类学建议并确定分类群划定的区分特征。我们使用分布在巴西、阿根廷和乌拉圭的 65 个种群的 675 个个体的 18 个形态特征进行了多变量和单变量形态计量分析，代表了 12 个形态类型，几乎涵盖了该复合体的所有形态多样性和地理分布。该小组提出了难以理解的形态模式，这表明该复合体不对应于单个物种，每个形态型也不对应于一个分类群。有可能只清楚地区分两个分类群，除了 H. parviflora 之外，由字符组合：H. paulensis 和 H. ulei。与花的大小、叶宽和萼片张开角度相关的特征对这两个物种来说是最具区别性的。其余形态类型的种群之间的关系在分析中表现出高度重叠，使得无法用所使用的特征来定义形态组。花的数量、子房长度和花结构之间的角度，以前没有用于这个复合体的分类，是识别分类群的重要特征，可以通过未来对组和属的分类学研究进一步探索。萼片的叶宽和张开角度对这两个物种最具区别性。其余形态类型的种群之间的关系在分析中表现出高度重叠，因此无法用所使用的特征来定义形态组。花的数量、子房长度和花结构之间的角度，以前没有用于这个复合体的分类，是识别分类群的重要特征，可以通过未来对组和属的分类学研究进一步探索。萼片的叶宽和张开角度对这两个物种最具区别性。其余形态类型的种群之间的关系在分析中表现出高度重叠，使得无法用所使用的特征来定义形态组。花的数量、子房长度和花结构之间的角度，以前没有用于这个复合体的分类，是识别分类群的重要特征，可以通过未来对组和属的分类学研究进一步探索。