New species and new combinations in Sonerila and Phyllagathis (Melastomataceae) from Thailand

While revising the Melastomataceae for the Flora of Thailand, we discovered two new species of Sonerila, as well as the need for transferring two species of Tylanthera endemic to Thailand into Phyllagathis. Sonerila urceolata and S. loeiensis are endemic to the southeast and the northeast of Thailand, respectively. The first is allied to the widespread S. erecta Jack, from which it differs mainly in the strongly urceolate capsule and the sessile fruit placenta; the second is distinguished from other acaulescent species of Sonerila by its extremely long-petiolate large leaves and long-pedunculate inflorescence. The new combinations, Phyllagathis tuberosa (Hansen) Cellinese and Renner and P. siamensis Cellinese and Renner nom. nov., are made because both taxa lie inside the morphologic and phylogenetic bounds of Phyllagathis.