1. Department of BotanyNational Museum of Natural History, MRC 166, Smithsonian InstitutionWashington DC 20013‐7012 USA
2. Key Laboratory of Plant Resources Conservation and Utilization, College of Biology and Environmental SciencesJishou UniversityJishou 416000 Hunan China
3. Herbarium (ALA), UA Museum of the North and Department of Biology and WildlifeUniversity of Alaska FairbanksFairbanks AK 99775 USA