Revision of the Southeast Asian genus Melastoma (Melastomataceae)

The monophyletic genus Melastoma (Melastomataceae) is centred in Southeast Asia, but extends to India, South China, Japan, northern Australia, and Oceania. It comprises 22 species, two subspecies, and three varieties. Two new species, Melastoma sabahense and M. minahassae, and a new variety, M. sanguineum var. ranauensis, are described; two species are reduced to subspecies and variety, respectively, and the genus Otanthera is transferred to Melastoma. In many species, especially M. malabathricum, morphological characters vary locally, which resulted in the taxonomic recognition of numerous geographically restricted entities here considered synonyms. Most species of Melastoma are pioneers with a high dispersal capacity. This may have resulted in small, relatively isolated populations in which unique character combinations were stabilised locally.