1. Key Laboratory of Plant Resource Conservation and Sustainable Utilization; South China Botanical Garden; The Chinese Academy of Sciences; Guangzhou 510650 China
2. Department of Ecology, Evolution, and Organismal Biology; Iowa State University; Ames IA 50011 USA
3. Department of Biology; University of Maryland; College Park MD 20742 USA
4. CEFE UMR 5175; CNRS; Université de Montpellier; Université Paul-Valéry Montpellier; EPHE; Montpellier France