关键词: 梵净山, 兰科, 分类, 区系

Abstract: A taxonomic and phytogeographical study of orchidaceae in the Fanjingshan is made based on the specimens collected in 1985-6 by Sino-English and Sino-American expeditions and deposited in the herbaria ofPE, GIB and Guizhou Insititure of Traditional Chinense Medical Science.49 species of 33 genera are recognized, of which 12 genera and 15 speciesare new to the mountains. The main features of the orchid flora are asfollows:1. The Fanjingshan orchid flora is rather rich, whose genera andspecies account for 50% and 27% of the total Guizhou orchids respectivelyand are richer than those in its neighbouring regions, such as JinfoshanMt. of Southeast Sinchuan and Sheninongjia region of west Hubei, butnext to those in Omei Mt. of southwest Sichuan. 2. Many tropical genera, such as Gastrochilus, Thrixspermum, Cleisostoma, etc. can be found here, mixed with temperate genera, such as Platanthera, Cymbidium etc. Eastern Asian genera are abundant. Examples are Pleione Epigenium, Bletilla, Cremastra, Amitostigma, Sedirea, Diphyllax, Pogonia etc.It shows a transition from tropical to temperate regions. 3. Phytogeographically, the orchid flora in the Fanjingshan isrelated to that in Japan rather than in the Himalayas. 26 species arecommon to both, and only 13 species there are also found in the Himalayas.

Key words: Fanjingshan, Orchidaceae, Floral features