Polystachya is a large, pantropical orchid genus of 200 species, most of which occur as epiphytes in sub-saharan Africa. The three-lobed labellum of most Polystachya species possesses a fleshy callus and various types of trichomes and papillae. In this paper, we present the results of micromorphological studies on the labellum of 20 species, representing eight of the 13 sections in the genus, using scanning electron microscopy (SEM). Our results show the scale of infrageneric diversity of trichomes and papillae relative to the sampled sections. They also demonstrate the taxonomic value of labellar micromorphology at the sectional level. The study revealed seven types of papillae and five types of trichomes (uni- and multi-cellular) in Polystachya, some of which, are described here for the first time. Clavate trichomes are the most common and are present in 60% of the species studied. Moniliform trichomes mainly occur in sect. Polystachya and are strongly characteristic of the section. Pseudopollen is formed by fragmentation of moniliform trichomes or the detachment of other trichomes as bicellular units. We provide, for the first time, evidence for the detachment of the terminal cells of capitate trichomes.

Polystachya是一个大型的泛热带兰花属，共有200种，其中大多数作为附生植物出现在撒哈拉以南非洲。多数Polystachya种类的三叶label具有肉质的愈伤组织以及各种类型的毛状体和乳突。在本文中，我们使用扫描电子显微镜（SEM）展示了20种物种的微形态学研究结果，这些物种代表了该属13个部分中的8个。我们的结果表明，毛状体和乳突的基础遗传多样性相对于所采样的切片而言。他们还证明了在剖面水平上小lar微观形态学的分类学价值。该研究揭示了Polystachya中的七种乳头和五种毛状体（单细胞和多细胞），其中一些是第一次在此进行描述。棒状毛状体是最常见的，并存在于60％的所研究物种中。念珠状毛状体主要发生在该部位。Polystachya和是该部分的强烈特征。假花粉通过单形毛状体的分裂或作为双细胞单位的其他毛状体的分离而形成。我们首次提供了关于人头毛的终末细胞脱离的证据。