Data from: Preliminary molecular phylogenetics of Sobralia and relatives (Orchidaceae: Sobralieae)

With over 200 species, the orchid tribe Sobralieae is a major constituent of the Neotropical flora. As currently circumscribed, the tribe includes four genera: Elleanthus, Epilyna, Sertifera, and Sobralia. Most species of these four genera typically produce long, cane-like stems but differ drastically in flower size and inflorescence structure. DNA sequence data support the monophyly of Elleanthus, Epilyna, and Sertifera but not Sobralia, which is a polyphyletic assemblage traditionally placed together due to relatively large flower size. Details of inflorescence structure provide characters that can easily distinguish the different clades of Sobralia. The misleading characteristic of flower size is probably due to at least several shifts in pollination syndrome within the tribe. With few exceptions, species of Sobralia predominantly offer no reward and are pollinated by bees. Elleanthus and Sertifera are small-flowered and mostly pollinated by hummingbirds with legitimate rewards. Nothing is known of pollination in Epilyna. Understanding the evolution of shifts in pollination syndrome will require more empirical observations of pollination within Sobralieae. In addition, increased taxon sampling and improved phylogenetic resolution are needed before generic realignments are made.

拥有超200个物种的索布拉兰族（Sobralieae）是新热带植物区系的主要组成类群。按当前的分类界定，该族包含4个属：埃兰属（Elleanthus）、隐柱兰属（Epilyna）、细穗兰属（Sertifera）以及索布拉兰属（Sobralia）。该四属的多数物种通常具细长的秆状茎，但在花大小与花序结构上差异显著。DNA序列数据支持埃兰属（Elleanthus）、隐柱兰属（Epilyna）与细穗兰属（Sertifera）为单系群，却不支持索布拉兰属（Sobralia）——后者是一个多系类群，传统上因花相对较大而被归为一类。花序结构的细节特征可作为区分索布拉兰属不同演化支的简易依据。花大小这一易造成误导的特征，可能源于该族内至少数次传粉综合征的演化转变。除少数例外，索布拉兰属的物种大多不提供传粉奖励，由蜜蜂传粉。埃兰属与细穗兰属的花较小，且大多由提供合法传粉奖励的蜂鸟传粉。目前对隐柱兰属的传粉机制尚一无所知。要阐明传粉综合征演化转变的机制，需对索布拉兰族开展更多的传粉实证观察。此外，在开展属级分类重定之前，还需增加类群取样量并提升系统发育解析度。