Malaxidinae are a cosmopolitan higher Epidendroid subtribe of > 1250 species that exhibit wide morphological and ecological diversity. Despite almost two centuries of taxonomic deliberation, controversy persists regarding the delimitation of practically all Malaxidinae genera, the most important of which are Crepidium, Dienia, Liparis and Malaxis. Previous attempts to classify these genera using a molecular phylogenetic approach showed Liparis and Malaxis to be polyphyletic and the floral characters traditionally used to define them as homoplastic. Emphasis has instead shifted to vegetative and ecological traits. Here, we conduct an expanded analysis of nuclear (ITS) and plastid (matK) sequences focused on terrestrial taxa, with the resulting phylogram largely corroborating the emerging picture, and we test the efficacy of four previously highlighted traits to recover the same relationships. Although growth habit is underscored as important for resolving a natural distinction between epiphytic Liparis and terrestrial ‘Crepidium clade’ plus ‘Malaxis clade’ taxa, leaf shape and venation and habitat preference are shown to be poor predictors of phylogenetic affiliation. Instead, perennating organ structure (heteroblastic or homoblastic) and placement (predominantly above- or below-ground) – are incisive, with leaf number and texture apparently correlated. These findings are discussed in the context of an inferred evolutionary history of the subtribe. Although homoplastic at the subtribe level, some floral characters are shown to be useful for resolving identities at the species level. Accordingly, the status of four long-confused species (Crepidium acuminatum, C. allanii, C. purpureum and Microstylis biloba) is resolved.

中文翻译：

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Crepidium (Orchidaceae, Epidendroideae, Malaxideae) 的综合分析揭示了它与 Dienia、Liparis 和 Malaxis 的关系，并证明恢复狭窄的地方性 C. allanii 是合理的

Malaxidinae 是一个世界性的高等表皮亚族，属于 > 1250 种表现出广泛的形态和生态多样性。尽管进行了近两个世纪的分类学审议，但关于几乎所有 Malaxidinae 属的划界仍存在争议，其中最重要的是 Crepidium、Dienia、Liparis 和 Malaxis。以前使用分子系统发育方法对这些属进行分类的尝试表明，Liparis 和 Malaxis 是多系的，而传统上用来将它们定义为同质的花特征。重点已转移到植物性状和生态性状上。在这里，我们对专注于陆地分类群的核（ITS）和质体（matK）序列进行了扩展分析，由此产生的系统图在很大程度上证实了新出现的画面，我们测试了四个先前强调的特征恢复相同关系的功效。尽管生长习性被强调对于解决附生 Liparis 和陆地“Crepidium clade”加“Malaxis clade”分类群之间的自然区别很重要，但叶子形状和脉络以及栖息地偏好被证明是系统发育隶属关系的不良预测因子。相反，多年生器官结构（异胚或同胚）和位置（主要是地上或地下） - 是精辟的，叶子数量和质地明显相关。这些发现是在推断的亚部落进化历史的背景下讨论的。尽管在亚部落水平上是同质的，但一些花卉特征被证明可用于在物种水平上解析身份。因此，