1. Department of Botany, MRC 166, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013-7012, USA.
2. Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Nanxincun 20, Xiangshan, Beijing 100093, P. R. China.
3. Laboratory of Biodiversity and Biogeography, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650204, P. R. China.
4. Graduate School of Chinese Academy of Sciences, Beijing 100039, P. R. China.
5. Department of Biological Science, School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan.