1. CAS Key Laboratory of Plant Germplasm Enhancement and Speciality Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China
2. Sino-Africa Joint Research Center, Chinese Academy of Sciences, Wuhan 430074, China
3. University of Chinese Academy of Sciences, Beijing 100049, China
4. East Africa Herbarium, National Museums of Kenya, P.O. Box 451660-0100, Nairobi, Kenya