Bulbophyllum orthosepalum J.J.Verm., Blumea 38 (1993) 145, fig. 3
Type: Jongejan cult. 414 (holo L)
Plant (not seen, reported to be identical to Bulbophyllum phalaenopsis but slightly smaller). Inflorescence usually single, c. 10 cm, c. 3-flowered. Peduncle c. 0.8 cm; the longest bract c. 12 mm. Rhachis c. 0.3 cm. Floral bracts approx. circular, 17-19 mm, tip acuminate. Pedicel and ovary c. 25 turn, with the node approx. at the same level as the floral bract. Flowers scattered, open simultaneously, hardly opening. Median sepal elliptic, c. 44 by 40 mm, index c. 1.1, tip acuminate; thick; glabrous. Lateral sepals connate from base to tip along their lower margins, oblique, obovate, c. 45 by 23 mm, index c. 1.9; otherwise as the median sepal. Petals ovate, c. 20 by 16 mm, index 1.2-1.3, tip acuminate; margins finely erose-papillose; thick; adaxially finely papillose towards the margins in the top part; abaxially glabrous. Lip moderately curved, general outline ovate, c. 1.4 by 0.9 mm, index 1.5-1.6 (not spread), tip acute; thick but rather soft; glabrous; adaxially moderately concave and with 2 distinct, rounded; converging ridges close to the base which continue as 2 inconspicuous, parallel ridges up to halfway the lip, top half approx. flat; abaxially with a distinct, retuse median ridge. Column from ovary to the tip of the stelidia c. 0.9 mm; stigma not protruding at its base, narrowly rectangular; column foot without accessories. Stelidia triangular, c. 0.3 mm; tip acute; with a small, deltoid, subacute tooth along the upper margin and a large, triangular, acute tooth along the lower margin. Anther abaxially with a conical ridge towards its tip; front margin not protruding. Pollinia 4; the inner pair more than half as long as the outer pair. Stipes absent. (After Vermeulen, 1993)
Colours: Flowers cream-coloured, but heavily mottled with purple.
Habitat: Epiphyte in lowland forest.
Distribution: Malesia (New Guinea).
Distribution in New Guinea: Papua New Guinea; see map 96-1322M.jpg.
Cultivation: Warm growing epiphyte.