Bulbophyllum leucothyrsus Schltr., Repert. Spec. Nov. Regni Veg. Beih. 1 (1913) 865
Type: Schlechter 17273 (holo B, lost; iso BM, K)
Rhizome pendulous, up to 60 cm long, 6-9 mm diam. Pseudobulbs ellipsoid to obovoid, 2.5-8 cm apart, 2.5-7 by 0.8-1.8 cm, moderately flattened. Petiole 1-15 mm. Leaf blade ovate to elliptic, 7.5-25 by 2.1-5.5 cm, index 2.7-6, tip acute. Inflorescence 3.8-22 cm, 4-19-flowered. Peduncle 1.5-3.5 cm; bracts 5-6, the longest 9-13 mm. Rachis 2.5-19 cm. Floral bracts triangular, 4.5-14 mm, tip acute. Pedicel and ovary 2-7 mm, with the node 0.3-4 mm from the floral bract. Flowers hardly opening. Median sepal ovate, 6-12 by 2.2-5 mm, index 2-3.2, tip subacute; thick; glabrous. Lateral sepals often adherent along their lower margins, oblique, 7-13 by 2-4 mm, index 2.5-5.5; otherwise as the median sepal. Petals ovate, 1.8-2.8 by 1.3-2.5 mm, index 1-2.2, tip obtuse to shortly acuminate; margins and often adaxial surface finely papillose; thick. Lip curved, general outline approx. rectangular to obovate, 0.9-1.5 by 0.6-1.2 mm, index 11.7 (not spread), tip rounded; margins finely papillose; thick; surface approx. glabrous to papillose; adx. without a basal concavity, basal teeth an inconspicuous, transverse ridge, basal part of the lip slightly distinctly concave, glabrous to slightly papillose, gradually passing into the convex, (slightly) papillose top part of the lip; abx. without a median ridge, surface glabrous. Column from ovary to the tip of the stelidia 0.7-1 mm; rostellum slightly protruding; stigma a transverse slit, not or slightly protruding at its base; column-foot approx. without accessories. Stelidia inconspicuous, triangular, tip acute. Anther abx. with a wide ridge; front margin hardly protruding. (After Vermeulen, 1993)
Colours: Sepals and petals white or cream-coloured, darkening to yellow with age. Lip white or pink.
Habitat: Epiphyte in lower montane forest; 500-1800 m.
Flowering time in the wild: February, July, October.
Distribution: Malesia (New Guinea).
Distribution in New Guinea: Papua New Guinea; see map 96-990M.jpg.
Cultivation: Intermediate growing epiphyte.