A taxonomic study of the genus Melinis (Poaceae) in Thailand was conducted. Two species, M. nerviglumis and M. repens, are found
with both species being introduced to Thailand. Melinis repens was introduced to Thailand for use as pasture and has become
naturalized in all floristic regions as a weed; M. nerviglumis has no record of utilization in Thailand and is recorded from the
Northern and North-Eastern regions but was not found during recent field surveys. Morphological descriptions, distribution data, and
ecological information are provided; lectotypes are designated for M. bachmannii, M. nyassana and M. villosipes, synonyms of
M. nerviglumis. Both species are illustrated and a key to the species, based on morphological characters is provided.