In Thailand two species of Dumasia occur, D. villosa subsp. villosa and D. yunnanensis. They grow in montane and dry evergreen forests, in open or disturbed areas and limestone ridges 550-2,500 meters above sea level, in northern, northeastern, and central Thailand. We present a key to the two Thai Dumasia based on their vegetative, flowering and fruiting characters, and provide nomenclature, descriptions, photographs, illustrations, and information about their distribution and ecology.
