Bulbophyllum olivinum J.J.Sm., Bot. Jahrb. Syst. 66 (1934) 205
Type: Stein 432 (not seen by Vermeulen 1993)
Rhizome creeping, 2-9 mm diam.; all rhizome scales slightly shorter to longer than the internodes. Roots in tufts below each pseudobulb. Pseudobulbs ovoid to orbicular, sometimes slightly lenticular, 2-9 cm apart, 1-3.5 by 0.6-1.8 cm, not laterally flattened. Petiole 8-45 mm. Leaf blade ovate to elliptic, 5.5-12 by 1.5-4 cm, index 2-6, tip obtuse to acute. Inflorescence 33-72 cm, 15-55-flowered. Peduncle 24-56 cm, bracts 5-8, the longest 7-12 mm. Rachis erect or arching, 4-16 cm. Floral bracts ovate, 3-8 mm, tip acute. Pedicel and ovary 10-15 mm, with the node 1.5-2.5 mm from the floral bract; ovary glabrous. Flowers few or many open at the time, widely opening. Median sepal ovate to elliptic, 6.5-10 by 3.5-6 mm, index 1.2-2.2, tip obtuse to shortly acuminate or apiculate; rather thin; glabrous. Lateral sepals oblique, 8-14 by 3.5-5.5 mm, index 1.62.6, tip obtuse to acute; otherwise as the median sepal. Petals oblique, approx. elliptic, 2.8-5 by 2-3.8 mm, index 1-1.6, tip obtuse to acute, or apiculate; margins glabrous or finely erose; thin; surface glabrous. Lip curved at the base, general outline approx. elliptic or spathulate, 2.8-5.5 by 1.5-2.5 mm, index 1.3-2.5 (not spread), tip rounded to acute; thick; glabrous; adx. concave near the base, with an inconspicuous to distinct median ridge which either bifurcates or is flanked by a shorter ridge on each side in the back, with 2 more distinct ridges converging and fused in front, in the basal half of the lip, into a median ridge; abx. with an inconspicuous, retuse median ridge. Column from ovary to the tip of the stelidia 1.2--1.8 mm; stigma with 3 distinct teeth at its base, orbicular; column-foot without accessories. Stelidia inconspicuous, triangular, tip obtuse to acute; upper margin erose; with a prominent, forwards pointing, triangular to semi-elliptic, rounded to acute tooth along the lower margin. Anther abx. with an inconspicuous ridge towards its base; front margin somewhat protruding. Pollinia 2. (After Vermeulen, 1993)
Colours: Pseudobulbs often suffused with purple. Sepals and petals yellowish green to apple green, suffused with purple or not (in particular in the centre); or entirely purple, sometimes with a yellow midvein. Lip yellow, pink or purple.
Habitat: Epiphyte in montane forest; 2000-2900 m.
Flowering time in the wild: January, February, March, April, May, September, October, November.
Distribution: Malesia (New Guinea).
Distribution in New Guinea: Papua (Indonesia); Papua New Guinea; see map 96-1297M.jpg.
Cultivation: Cool growing epiphyte.