1. Eastern China Conservation Centre for Wild Endangered Plant Resources, Shanghai Chenshan Botanical Garden , Shanghai, 201602 , China
2. Plant Phylogenetics and Conservation Group, Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences , Kunming, 650223 , China
3. State Forestry and Grassland Administration Key Laboratory of Silviculture in Downstream Areas of the Yellow River, College of Forestry, Shandong Agricultural University , Tai’an, 271018 , China
4. Department of Biology and Botanic Garden, University of Fribourg , Fribourg, CH-1700 , Switzerland
5. Natural History Museum Fribourg , Fribourg, CH-1700 , Switzerland