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.

拥有超过200个物种的索不拉兰族（Sobralieae）是新热带区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）、埃皮兰属（Epilyna）、塞特费拉兰属（Sertifera）以及索不拉兰属（Sobralia）。上述4个属的多数物种通常会长出细长的茎秆状结构，但在花部尺寸与花序结构上存在显著差异。DNA序列数据支持埃兰属、埃皮兰属与塞特费拉兰属为单系群，但不支持索不拉兰属，该属是一个因花部尺寸相对较大而被传统归为一类的多系群。花序结构的细节特征可作为区分索不拉兰属不同演化支的简易依据。花部尺寸这一易造成误导的特征，可能源于该族内传粉综合征至少数次的演化转变。除少数例外，索不拉兰属的绝大多数物种不提供回报物，其传粉者为蜂类。埃兰属与塞特费拉兰属的花朵尺寸较小，且多数依靠蜂鸟传粉，同时会提供真实的回报物。目前对埃皮兰属的传粉机制尚一无所知。要阐明传粉综合征的演化转变，需要针对索不拉兰族开展更多的传粉生态学实地观测。此外，在进行属级分类调整前，还需要增加类群采样量并优化系统发育分辨率。