Fig. 4

Geographical distribution of B. officinalis (blue) and B. crispa (red) in China, based on locality information of 710 specimens (474 B. officinalis and 236 B. crispa); data for the specimens were obtained from the Chinese Virtual Herbarium (http://www.cvh.org.cn, accessed Aug 22, 2014), and all available specimens were included. B. crispa is predominantly found at altitudes >2000 m, while B. officinalis grows mostly at lower altitudes. The location of the study site is indicated with a star