Ponerorchis wolongensis (Orchidaceae, Orchidinae), a new species with variable labellum from Hengduan Mountains, western Sichuan, China

Ponerorchis wolongensis, a new orchid species from the Hengduan Mountains, western Sichuan, China, is described and illustrated here based on morphological and phylogenetic evidence. Morphologically, the new species is similar to P. capitata, but they can easily be differentiated by the number of leaves and flowers, the shape of leaves, and the mid-lobe of the labellum. Phylogenetically, based on seven DNA sequences, the new species is more close to P . sichuanica, but these two species are very different in both growth habit and morphological characteristics.

本研究基于形态学与系统发育证据，对产自中国四川西部横断山区的兰科新种卧龙无柱兰（Ponerorchis wolongensis）进行了描述与图解。形态学上，该新种与头序无柱兰（Ponerorchis capitata）相似，但可通过叶片数、花数、叶片形状以及唇瓣中裂片的形态特征轻易区分二者。系统发育层面，基于7个DNA序列的分析显示，该新种与四川无柱兰（Ponerorchis sichuanica）亲缘关系较近，但二者在生长习性与形态特征上均存在显著差异。