Three new species of Bredia (Sonerileae, Melastomataceae) from the Sino-Vietnamese border area

Brediabullata, B.enchengensis, and B.nitida (Sonerileae, Melastomataceae), three species occurring in Sino-Vietnamese limestone karst regions, are described as new. Molecular phylogenetic analyses and morphological divergence indicate that these species are well separated from their close relatives in Bredia, justifying their recognition as distinct species. Brediabullata is unique in its interveinal areas prominently bullate each with an apical seta, a character otherwise never recorded in the genus. Bredianitida resembles B.malipoensis in habit, leaf shape, and inflorescence morphology, but differs in the glabrescent and nitid adaxial leaf surface (vs. densely pubescent and subvelvety), ovate-elliptic or elliptic calyx lobes (vs. triangular to semiorbicular), and white petals (vs. purplish-red). Brediaenchengensis is closest to B.longiradiosa, but easily recognized by its prostrate habit (vs. erect), the yellowish-green, membranous and fragile leaves (vs. green or dark green, papery), and white anthers (vs. pink to purplish). These new discoveries show that further botanical exploration is warranted in the remote Sino-Vietnamese bordering region.