1. B. tripudians Parish & Reichenbach (1875: 154), Seidenfaden (1970: 341, 1979: 189), Ormerod et al. (2021: 50). Type:— MYANMAR. Mon State: Mawlamyine District, Parish 308 (K000829091 photo!).

≡ B. tripudianthe Shaw (2016: 124), nom. superfluum.

≡ Tripudianthes tripudians (Parish & Reichenbach 1875: 154) Szlachetko & Kras (2007: 96) .

Habitat and phenology: —Epiphyte on tall trees in broad-leaved evergreen forest. Flowering observed in February– March.

Distribution: — Myanmar, Thailand, Laos, Vietnam (?).

Proposed conservation status:—According to currently available data, B. tripudians is a very rare species recorded from a single collection made by Poilane in 1933. More field studies are necessary for the identification of its conservation status. In view of lack of current data and in accordance with IUCN criteria (IUCN, 2022), the species should be assessed as Data Deficient (DD).

Note: —The occurrence of this species in Vietnam is based on a single collection by Poilane (P00362016) made in Lam Dong Province, in Bao Loc District. However, specimens on the herbarium sheet (especially on the rightside) show a large dorsal sepal do not attenuate at apex that is typical for B. refractum, hence the identification on our opinion may be doubtful.

Studied specimens: — VIETNAM, Lam Dong Province, “Annam: un peu au sud de la station agricole de Blao, prov. du Haut Donaï”, 1933, Poilane, 22157 (P00362016 photo!).