Bulbophyllum macilentum J.J.Verm., Orchid Monogr. 7 (1993) 134, fig. 88
Type: Reeve 2862 (holo L; iso K)
Rhizome approximately pendulous, to 50 by 0.2-0.3 cm diem. P.seudobulhs ovoid to cylindrical, 1-3.8 cm apart, 1.8-4 by 0.2-0.5 cm, not or hardly flattened. Petiole 2-6 mm. Leaf blade ovate to elliptic, 2-7.5 by 0.2-0.6 cm, index 7.5-13; tip acute. Inflorescence 2-6 cm, 4-7-flowered; peduncle 0.7-1.5 cm. Floral bracts c. 3. the longest 6-9 mm. Rachis 1.3-5.3 cm. Floral bracts ovate to triangular, 2-4 mm; tip acute. Pedicel and ovary 1.5-3 mm, with the node 0.05-0.1 cm from the floral bract. Flowers widely opening. Median sepal (ob)ovate to elliptic, 2.2-3 by 0.8-1 mm, index 2.2-3; tip acuminate; rather thin, glabrous. Lateral sepals free, oblique, ovate to elliptic, 2.2-3 by 0.8-1 mm, index 2.2-3.5; otherwise as the median sepal. Petals oblique, elliptic to obovate, 1.2-1.5 by 0.7-0.8 mm, index 1.7-2; tip obtuse to shortly acuminate, margins slightly erose, thin; surface glabrous. Lip slightly curved near its base, general outline approximately elliptic to obovate, 1-1.4 by 0.4-0.7 mm, index 1.7-3.5 (not spread); tip rounded; very thick, glabrous or locally slightly papillose; adaxially with a basal concavety, basal teeth converging, together forming a transversely ridge with a notch or a shallow slit half-way, basal part of the lip distinctly concave, gradually passing into the convex top part of the lip; abaxially without a median ridge. Column from ovary to the tip of the stelidia 0.4 mm; rostellum not protruding; stigma orbicular, slightly protruding at its base. Column-foot with an incurved, rounded central knob above the attachment of the lip. Stelidia inconspicuously, semi-elliptic; tip rounded. Anther abaxially with a broad ridge, front margin not protruding. (After Vermeulen, 1993)
Colours: Sepals and petals white, or pale yellowish. Lip yellow.
Habitat: Epiphyte in lower montane forest; 1540-1800 m.
Flowering time in the wild: August, October.
Distribution: Malesia (New Guinea).
Distribution in New Guinea: Papua New Guinea; see map 96-1069M.jpg.
Cultivation: Intermediate growing epiphyte.