1. Plant Phylogenetics and Conservation Group, Centre for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, 650223, P. R. China
2. College of Agro-biological Resource Sciences, University of Tsukuba, Tsukuba 305-8577, Japan
3. Tsukuba Botanical Garden, National Museum of Nature and Science, Tsukuba 305-0005, Japan