1. Department of Botany; National Museum of Natural History; MRC-166, Smithsonian Institution Washington, DC 20013-7012 USA
2. Institute of Agricultural Economy and Information; Hubei Academy of Agricultural Sciences; Wuhan 430064 China
3. National Field Station of Freshwater Ecosystem of Liangzi Lake; College of Life Sciences, Wuhan University; Wuhan 430072 China
4. College of Life Sciences; Shaanxi Normal University; Xi'an 710119 China
5. Agriculture School; Kunming University; Kunming 650214 China