Nephoanthus (Melastomataceae: Sonerileae), a new genus segregated from Phyllagathis s.l., with a new species from Southern Vietnam

A new genus, Nephoanthus, is established based on morphological and molecular data. It comprises two species distributed in montane forests of central to southern Vietnam and Hainan Island: the type species N. prostratus and a new species N. nubigenus. Nephoanthus is morphologically similar to Phyllagathis but phylogenetically remote from the type species of Phyllagathis in the analyses of both plastid genome and nrITS sequences. Nephoanthus is genetically associated to but significantly morphologically distinct from Driessenia, Heteroblemma, Medinilla and Tigridiopalma. A detailed morphological comparison of Nephoanthus and related taxa is provided.