Bulbophyllum bigibbum Schltr., Bot. Jahrb. Syst. 58 (1923) 137
Type: Ledermann 10123 (holo B, lost; iso K, L)
Rhizome patent to pendulous, up to 30 cm long, 0.7-1 mm diam. Roots present only below the pseudobulbs, along the older parts of the rhizome. Pseudobulbs ovoid, 0.5-2 cm apart, 0.3-0.8 by 0.2-0.4 cm, not flattened. Petiole c. 1 mm. Leaf blade ovate to elliptic, 1-3 by 0.2-0.4 cm, index 4-10, tip acute. Inflorescences usually many together on a short sympodium, c. 1 cm, 1-flowered. Peduncle c. 0.2 cm; bracts c. 3, the longest c. 1.6-2 mm. Floral bracts tubular, 1.2-1.5 mm, tip acute. Pedicel and ovary 1.8-3 mm, with the node c. 0.5 mm from the floral bract. Flowers widely opening. Median sepal ovate to elliptic, 2-4.5 by 1.4-2 mm, index 1.5-2.3, tip subacute; thin; glabrous. Lateral sepals oblique, 2-3.8 by 1.5-2 mm, index 1.2-1.9, otherwise as the median sepal. Petals slightly oblique, ovate to elliptic, 1.5-2 by 1-1.2 mm, index c. 1.5, tip obtuse; thin; glabrous. Lip strongly curved, general outline ovate, 0.8-1.2 by 0.7-1 mm, index 1-1.2 (not spread), tip obtuse; rather thin; glabrous; adx. somewhat concave and with 2 distinct knobs near the base, convex towards the tip; abx. with an inconspicuous, retuse median ridge. Column from ovary to the tip of the stelidia c. 0.7 mm; stigma not protruding at its base, slit-like. Stelidia absent or inconspicuous, with a distinct, large, obtuse, tooth along the upper margin. Anther abx. with an inconspicuous ridge towards its base; front margin protruding. Pollinia 4; the inner pair more than half as long as the outer pair.
(After Vermeulen, 1993)