Leonid V. Averyanov, Khang Sinh Nguyen, Ba Vuong Truong, Van Canh Nguyen, Tatiana V. Maisak, Tran Huy Thai, Pham Thi Thanh Dat & Bao Ngan Tu
Bulbophyllum layae Photo: T. Ba Vuong
Bulbophyllum metallica Photo: L. Averyanov
Bulbophyllum papilligerum Photos: D. Slastunov & L. Averyanov
Bulbophyllum alcicorne Photos: Nguyen Van Canh
Abstract: Three species, Bulbophyllum layae, Bulbophyllum metallica and Bulbophyllum papilligerum (all from sect. Cirrhopetalum) are described as new for science. All of these novelties are local endemics of limestone areas of northern Vietnam. Additionally, three species, Bulbophyllum alcicorne (sect. Brachystachya), Bulbophyllum psittacoglossum and Bulbophyllum yunnanense (both from sect. Sestochilus) are recorded for the flora of Vietnam for the first time. These species have wide distribution in mainland Asia. Data on ecology, phenology, distribution, brief relevant taxonomic notes, as well as color photographs, analytical plates of the type and voucher specimens are provided for all reported taxa. Lectotypification is provided for Bulbophyllum yunnanense.
Bulbophyllum layae superficially resembles juvenille specimens of widespread and variable B. pecten-veneris
(Gagnepain 1931: 6) Seidenfaden (1974: 37), but well differs in short inflorescence scape, as long, or little longer than flowers (vs. scape much longer than flowers), small flowers 2.5–3 cm long (vs. flowers more than 4 cm long) and dense setose white hairiness of basal half of the lip (vs. lip with no hairs). Very few known about new species ecology. Most probably new species like B. pecten-veneris inhabits limestone forests at elevation 500–1500 m.
Bulbophyllum metallica belongs to Bulbophyllum sect. Cirropetalum s.l. on the base of its floral morphology and formally allies to the group of species having short scape, few-flowered loose umbel-like inflorescence, entire margin of sepals and petals, simple lip and lateral sepals twisted at the base and connate on lower and upper edges. In eastern Indochina such combinations of morphological features exhibit such species as B. seidenfadenii A.D. Kerr, B. spathulatum (E.W. Cooper) Seidenf. and B. unciniferum Seidenf. From these species (as well as from other members of the section Cirropetalum) our plant strikingly differs in pendulous stems to 1.5 m long, narrowly cylindric, petiolelike pseudobulbs to 7 cm long (3–5.5 mm in diameter), long down hanging coriaceous leaves to 40 cm long with blue-green metallic shine on adaxial side and very shot scape, less than 1.5 cm long. Fleshy, hardly opening, white, purple speckled flowers are also very distinct from all other species known in Indochina. Even sterile plants are easy recognizable for amazing metallic blue or blue-green shining of adaxial leaf surface. For this remarkable character, plant was noted as a new species already in 2001 (LE01042169). However, plants with flowers used for appropriate description were found only seventeen years later. According to available data, new species is very rare plant growing usually along mountain streams in particular humid habitats.
Bulbophyllum papilligerum may be attributed to Bulbophyllum sect. Cirropetalum on the base of its obvious floral morphology. Among species of this section, it may be solely compared with Bulbophyllum flaviflorum (Tang, S. Liu & H.Y. Su) Seidenf., Bulbophyllum hirundinis (Gagnep.) Seidenf. and Bulbophyllum pecten-veneris (Gagnep.) Seidenf. (and Bulbophyllum fimbriperianthium W.M.Lin, Kuo Huang & T.P.Lin) From these species, discovered plant differs in erect scape (vs. scape pendulous or horizontal, down arching), headlike inflorescence (vs. umbellate inflorescence when flowers are spaced in one plane), smaller flowers 1.4–1.5 cm long (vs. flowers longer than 2 cm), lateral sepals free along lower margin, slightly broadening to obtuse or blunt apex (vs. lateral sepals joined along lower margin, tapering to acuminate or caudate apex), petals round at apex (vs. petals acute), bunch of fat long papillae on abaxial surface near petal apex (vs. petals ciliate or fimbriate along the margin, hairless on abaxial surface), adaxial surface of petal apex with many dense short conical glass-like papillae (vs. petal surface with no particular glass-like papillae), nor particular stelidia (vs. stelidia prominent, subulate), anther margin slightly erose (vs. frontal anther margin distinctly denticulate or fimbriate).
Published in Phytotaxa 404 (6): 231–244