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

<i>Vaccinium bidoupense</i>, 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 <i>V. petelotii</i> and <i>V. pseudobullatum</i> 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 <i>V. bidoupense</i> is further supported by its allopatric distribution relative to both <i>V. petelotii</i> and <i>V. pseudobullatum</i>. The range of morphological variation of <i>V. petelotii</i> and <i>V. pseudobullatum</i> is clarified, and their analytical photographic images are published for the first time. Additionally, the distinction between indeterminate and determinate racemes in <i>Vaccinium</i> is revisited, and the taxonomic history of Vaccinium sect. Calcicolus is summarized.