Bulbophyllum sect. Brachyantha

Averyanov, Leonid V., Nguyen, Van Canh, Vuong, Truong Ba, Nuraliev, Maxim S., Nguyen, Khang Sinh, Maisak, Tatiana V., Yudova, Daria A., Saidov, Nikita T., Nguyen, Cuong Huu & Nong, Duy Van, 2024, New orchids in the flora of Vietnam VIII (Orchidaceae: Epidendroideae, tribes Malaxideae, Neottieae and Podochileae), Phytotaxa 658 (1), pp. 1-49 : 4

Bulbophyllum sect. Brachyantha

Bulbophyllum lasiochilum C.S.P.Parish & Rchb.f. in Reichenbach (1874: 153), Seidenfaden & Smitinand (1961: 353), Seidenfaden (1973a: 154, 1979: 170), Seidenfaden & Wood (1992: 451), Schuiteman et al. (2008: 268), Clayton (2017: 66), Aung et al. (2020: 64), Ormerod et al. (2021: 37).

( Fig. 3 )

Type: — MYANMAR. Mon State: Mawlamyine District, C. S. P. Parish 307 ( lectotype, designated by Clayton (2017: 66): K K000829977 photo!; isolectotype: W-R; icon. W-R 2282) .

Habitat and phenology in Laos and Vietnam: —Creeping epiphyte. Primary and old secondary humid broad-leaved forests on sandstone and shale at elevation of 600–700 m a.s.l. In Laos occasional, in Vietnam very rare. Flowers in January and June.

Distribution: — Vietnam: Dien Bien Province (Nam Po District). S Myanmar, Thailand, Laos, Peninsular Malaysia.

Conservation status in Laos and Vietnam: —In Eastern Indochina, three distant localities of Bulbophyllum lasiochilum are known: two in Laos (provinces Khammouane and Bolikhamsai) and one in Vietnam (Dien Bien Province). In some of them, the species is reported to be common. However, considering the severe fragmentation of its known populations, we estimate the conservation status of the species in Laos and Vietnam as Near Threatened (NT).

Notes: — Bulbophyllum lasiochilum is highly distinct for its single-flowered inflorescence, large flowers, and long-ciliate petals and lip. This species is reported here as a new record for the flora of Vietnam. In Laos, this species was previously known from a single location in Khammouane Province ( Newman et al. 2007, Schuiteman et al. 2008). The localities from Laos and Vietnam reported here essentially expand the distribution area of the species in Eastern Indochina.

Studied specimens:— LAOS. Bolikhamsai Province: Khamkeut District, Phone Sa At Village, around point 18°03’38”N 105°02’28”E, remnants of primary wet closed broad-leaved forest on steep slope of mountains composed with sandstone and shale at elevation of about 635 m a.s.l., creeping epiphyte on tall trees, flowers solitary, pale dull brownish, locally very common, 18 January 2009, S. Bounphanmy, N.T. Hiep, L. Averyanov, V. Lamxay, P.K. Loc, N.Q. Hieu, LA-VN 26 (LE LE01055688 https://en.herbariumle.ru/?t=occ&id=7352, photos LE LE01087117 https:// en.herbariumle.ru/?t=occ&id=18641, LE01122684 https://en.herbariumle.ru/?t=occ&id=94973). VIETNAM. Dien Bien Province: Nam Po District, epiphyte, flowers fragrant, petals and lip with hairy margins, 28 June 2023, Truong Ba Vuong, BV 1817 (VNM 00070002, LE LE01253779 https://en.herbariumle.ru/?t=occ&id=211978, photos LE LE01124286 https://en.herbariumle.ru/?t=occ&id=185343).

Figures

FIGURE 3. Bulbophyllum lasiochilum. A. Flowering plants. B. Flattened plants. C. Flowers, half-side and front views. D. Flowers, side and rear view. E. Median sepal, adaxial and abaxial side. F. Lateral sepals, adaxial and abaxial side. G. Petals, adaxial and abaxial side. H. Lip, views from different sides. I. Pedicel, ovary, column and column foot, side view. J. Column, column foot and lip, side view. K. Column and column foot, side view. L. Column, front view. Photos by Truong Ba Vuong from living plant prior to the preparation of the voucher herbarium specimen Truong Ba Vuong, BV 1817. Photo correction and design by L. Averyanov and T. Maisak.