Universidade Federal do Rio Grande do Sul, Instituto de Biociências, Departamento de Botânica, Programa de Pós-graduação em Botânica, Av. Bento Gonçalves 9500, RS 91501-970, Porto Alegre, Rio Grande do Sul, Brazil.
Ann Bot. 2012 Jan;109(1):135-44. doi: 10.1093/aob/mcr241. Epub 2011 Sep 20.
Capanemia Barb. Rodr. comprises seven species that mostly inhabit the Brazilian Atlantic Rain Forest domain. The genus currently consists of two sections: Capanemia Cogn. and Planifolia Pabst, distinguished on the basis of leaf shape. We compare the floral morphology and anatomy of all species to determine whether separation into sections is supported by floral characters.
Both fresh flowers and herbarium specimens were investigated, and column and pollinarium features, together with the presence or absence of floral rewards, recorded. Anatomical features were examined using both light microscopy and scanning electron microscopy.
With the sole exception of Capanemia therezae, all species shared a distinctive set of floral characters. Flowers were mostly white or yellowish-white and fragrant, and column wings were positioned parallel to the labellum, concealing the stigmatic cavity. Pollinaria had proportionally long tegular stipes and clavate to reniform pollinia, whereas the labellum possessed a conspicuous indument of trichomes, but was devoid of nectar or any other secretion that might function as a food-reward. Capanemia therezae, however, was exceptional in having greenish, unscented flowers with short, rounded and divergent column wings and an exposed stigmatic cavity. Its pollinaria had proportionally short tegular stipes and round pollinia, whereas the labellum lacked trichomes. Droplets of nectar were evident on the adaxial surface of the labellum, adjacent to the callus. Floral features did not support the currently accepted sectional division of Capanemia. If ongoing phylogenetic studies demonstrate that both sections are indeed monophyletic, then these taxa should be distinguished solely on the basis of foliar features.
Capanemia Barb. Rodr. 由七个主要栖息在巴西大西洋雨林区的物种组成。该属目前分为两个节：Capanemia Cogn. 和 Planifolia Pabst，根据叶片形状区分。我们比较了所有物种的花形态和解剖结构，以确定花的特征是否支持它们分为两个节。
我们调查了新鲜花朵和标本，记录了柱和花粉块的特征，以及花奖励的存在或不存在。使用光学显微镜和扫描电子显微镜检查了解剖学特征。
除了 Capanemia therezae 外，所有物种都具有独特的花形态特征。花朵大多为白色或淡黄色，有香味，柱翅与唇瓣平行，隐藏着柱头腔。花粉块具有相对较长的翼状龙骨和棍棒状到肾形的花粉粒，而唇瓣具有明显的毛状毛，但是没有花蜜或任何其他可能作为食物奖励的分泌物。然而，Capanemia therezae 是例外的，它具有绿色、无味的花朵，柱翅短、圆形且发散，暴露的柱头腔。它的花粉块具有相对较短的翼状龙骨和圆形的花粉粒，而唇瓣没有毛。花蜜滴在唇瓣的腹面可见，靠近胼胝体。花的特征不支持目前对 Capanemia 的节的划分。如果正在进行的系统发育研究表明两个节确实是单系的，那么这些分类群应该仅根据叶片特征来区分。
