1. Key Laboratory of Biodiversity and Biogeography; Kunming Institute of Botany, Chinese Academy of Sciences; Kunming, Yunnan 650204 P.R. China
2. Institute of Tibet Plateau Research at Kunming; Chinese Academy of Sciences; Kunming, Yunnan 650204 P.R. China
3. Department of Botany, National Museum of Natural History; Smithsonian Institution; Washington, D.C. 20013-7012 U.S.A.
4. Laboratory of Systematic and Evolutionary Botany, Institute of Botany; Chinese Academy of Sciences; Nanxincun 20 Xiangshan, Beijing 100093 P.R. China