Bulbophyllum chrysolabium

Description. Epiphytic herbs. Rhizome rigid, creeping, 2 - 3 mm thick. Pseudobulbs borne on rhizome at an interval of 3 - 5 cm, ovoid to narrowly ovoid, 2.2 - 3.5 cm high, base often covered with remnant fibrous sheaths. Leaf apical, single, coriaceous, oblong to linear-oblong, 12 - 14 cm x 1.8 - 2.2 cm, subsessile, apex retuse or minutely notched. Inflorescences developing from base of pseudobulb, with pendulous densely many-flowered raceme; scape 5 to 6 cm long, nearly completely enveloped by 4 or 5 sterile, broadly ovate sheaths; sheath 1.5 - 1.8 cm long, scaled, light brownish; rachis about 6.5 cm long, with many flowers spirally arranged into a compact spike-like cylindrical raceme, opening simultaneously; floral bracts light brownish, dry papyraceous, oblong-lanceolate, ca. 6.5 mm long, almost twice as long as the pedicel and ovary, apex apiculate; pedicel and ovary ca. 3.5 mm, longitudinally slightly grooved. Flowers resupinate, not much opening, with unpleasant fishy smell. Sepals 3 - 6 - veined, greenish-yellow, without spots or stripes. Dorsal sepal oblong-ovate or narrowly ovate, 4.5 - 5.0 mm x 1.0 - 1.5 mm, 3 - veined, abaxially sparsely papillate, apex shortly aristate or apiculate, often recurved. Lateral sepals obliquely oblong-ovate, 5.5 - 6 mm x 2.0 - 2.5 mm, 5 - 6 - veined, abaxially sparsely papillate, base adnate to column foot, margins strongly involute, with the apex shortly caudate, loosely adhering along the lower edges, forming an ovoid sac. Petals pale greenish-yellow, obliquely and broadly-based triangular, apex long acuminate, tapering into a long filiform or threadlike tail, usually contorted to spirally twisted, 2.0 - 2.2 mm x 0.8 - 1.0 mm near the base, with a tail 2.8 - 3.0 mm long, margins somewhat irregularly denticulate or erose. Lip yellowish-orange or deep golden yellow, fleshy, oblong narrowly ovoid, 2.5 - 2.8 mm x 1.3 - 1.5 mm, mobile on a thin ligament, recurved near the base, conspicuously auriculate at the base; disc with a longitudinal central groove, apex rounded or obtuse; auricles narrowly falcate, arching forward and gradually tapering to a long sharp point at the apex; densely glandular pap illose on both sides and conspicuously ciliolate along margins, whitish. Column greenish-yellow, subcylindric, 2.0 - 2.2 mm tall; foot ca. 1.5 mm; stelidia well-developed and subulate, ca. 1.2 mm, often twisted inwards, equalling or slightly exceeding operculum, with a sharp point along the upper margin. Anther abaxially with a rounded crest, golden-yellow. Pollinia 4, the inner ones more than half as long as the outer ones.