Abstract:Themeda Forssk. (Poaceae) is one of the key groups for systematic study of the tribe Andropogoneae exhibiting considerable morphological and ecological diversity, the genus is one of representative groups of spathaceous species in the tribe. The geographical distribution of Themeda was investigated by means of reviewing herbarium specimens and literature and field investigations. About a total of 27 drought-tolerance species were distributed in dry and hot areas of tropics and warm subtropics of the Old World, and three species (sect. Themeda) had extended to the New World. In China, thirteen species were distributed in southwestern and southern provinces, and 10 species occurred in dry-hot valleys of Yunnan. The results suggested that Northern India and Yunnan of China were the present distribution centers and diversification centers, while the origin center of Themeda needed to be further studied.
