Bulbophyllum sect. Tripudianthes Seidenfaden (1979: 188) .

Type:— B. tripudians Parish & Reichenbach (1875: 154) .

= Tripudianthes Szlachetko & Kras (2007: 94) .

10–11 species in Nepal, Bhutan, NE India, Myanmar, S China, Thailand, Laos, Vietnam, Java, and Sumatra. In Vietnam 3–5 species, 1 endemic.

Identification key to species of Bulbophyllum section Tripudianthes reported in the flora of Vietnam Species, the occurrence of which needs confirmation are designated by asterisk (*)

1. Median sepal with entire margin ........................................................................................................................................................2

–. Median sepal with ciliate or fimbriate margin....................................................................................................................................4

2. Median sepal attenuate, with filiform appendage at apex ................................................................................................. B. wallichii

–. Median sepal acuminate, rarely with short seta at apex .....................................................................................................................3

3. Median sepal ovate, acuminate; lateral sepals 3–5.5 cm long; petals acuminate.......................................................... B. tripudians *

–. Median sepal narrowly ovate, acute; lateral sepals ca. 2.5 cm long; petals aristate .................................................. B. kanburiense *

4. Median sepals ovate, attenuate................................................................................................................................. B. viridipallidum

–. Median sepal elliptic, obtuse to acute............................................................................................................................... B. refractum