1. State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany Chinese Academy of Sciences Beijing 100093 China
2. College of Life Sciences University of Chinese Academy of Sciences Beijing 100049 China
3. College of Forestry Central South University of Forestry and Technology Changsha 410004 China
4. Meise Botanic Garden BE‐1860 Meise Belgium
5. Department of Biology KU Leuven BE‐3001 Leuven Belgium