Bulbophyllum sect. Cirrhopetalum (Lindl.) Reichenbach (1861: 259) ≡ Cirrhopetalum Lindley (1830: 45, 58), id. (1824 sub pl. 832), nom nud. Type:— C. thouarsii Lindley (1830: 58), nom. illeg. (= B. longiflorum Thouars 1822 t. 98). 10 accepted species (Vermeulen 2015). In Vietnam 4 species (1 endemic). Key to species of Bulbophyllum sect. Cirrhopetallum s. str. in Vietnam 1 Dorsal sepal with long clavate seta, 5–8 mm long; petals papillose ..................................................................................................2 - Dorsal sepal with short, simple seta, less than 2 mm long; petals not papillose................................................................................3 2 Petal apex somewhat truncate, margin with few hairs only in apical part; lip auriculate, finely hairy at the base.............................. ................................................................................................................................................................................... 1. B. annamense - Petal apex acute, margin fimbriate throughout; lip simple, entirely glabrous.......................................................... 2. B. longiflorum 3 Lateral sepals finely papillose; petals shortly fimbriate at apex............................................................................... 3. B. fenestratum - Lateral sepals warty to colliculate; petals hardly denticulate or erose at apex.................................................................4. B. thangii

Published as part of Truong, Ba Vuong, Averyanov, Leonid V., Maisak, Tatiana V., Dang, Minh Quan, Nguyen, Van Canh, Amlser, Roland, Nguyen, Quoc Bao & Dang, Van Son, 2023, Bulbophylum sect. Cirhopetallum s. str. (Orchidaceae) in Vietnam with the description of a new species, B. thangii, and a new national record, B. fenestratum, pp. 201-210 in Phytotaxa 625 (2) on page 202, DOI: 10.11646/phytotaxa.625.2.6, http://zenodo.org/record/10150886