Vaccinium bidoupense (Ericaceae), a new species from Vietnam and Laos, with notes on V. petelotii and V. pseudobullatum.

Vaccinium bidoupense, a new species of Ericaceae from the Central Highlands of Vietnam and their vicinity in Laos, is described and illustrated. The new species is morphologically similar to V. petelotii and V. pseudobullatum in its relatively large leaf blades and umbel-like inflorescence but differs in having the following combination of characters: pale red to salmon pink corollas, and longer pedicels, calyx lobes, corolla tubes and stamen filaments. The distinctness of V. bidoupense is further supported by its allopatric distribution relative to both V. petelotii and V. pseudobullatum. The range of morphological variation of V. petelotii and V. pseudobullatum is clarified, and their analytical photographic images are published for the first time. Additionally, the distinction between indeterminate and determinate racemes in Vaccinium is revisited, and the taxonomic history of Vaccinium sect. Calcicolus is summarized.