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.