Diplocaulobium inconstans (J.J.Sm.) Kraenzl., in Engl., Pflanzenr. IV. 50. II. B. 21 (1910) 341.
Basionym: Dendrobium inconstans.
Pseudobulbs crowded, 1-leaved, at the base ovoid-fusiform, in upper part very slender, elliptic in cross section, slightly widened to the apex, 10 cm long, of which the swollen basal part c. 4 cm long, 1.3 cm wide in basal part, 0.25 wide in upper part. Leaves erect, narrowly lanceolate, 10 by 2.2 cm, base conduplicate, apex bidentate, coriaceous, grooved along the midvein, keeled below. Inflorescences arising in succession from the apex of the pseudobulb, 1-flowered, spathe laterally flattened, 2.3 cm long; peduncle 1.1 cm long. Floral bract triangular, minute. Pedicel 2.7 cm long; ovary 0.3 cm long, 6-grooved. Flower resupinated, c. 4.6 cm across, ephemeral. Dorsal sepal narrowly linear, widened to the base, 3.2 cm by 5 mm, concave, apex acute. Lateral sepals oblique, narrowly linear, widened to the subfalcate-triangular base, 3.2 cm by 7 mm, apex acute; concave, mentum c. 0.5 cm long. Petals linear-filiform, a little widened to the base, 2.85 cm long, 2 mm wide at the base, in the middle 0.5 mm wide, concave, apex acute. Lip 3-lobed in the middle, 1.13 by 0.65 cm, cuneate at the base, with 2 flat, broad, glabrous basal keels extending to the base of the midlobe, the keels separated by a groove, acute at their point of termination, the midlobe inside rugulose and with a low, weakly 3-ribbed median swollen band; lateral lobes erect, subtrapeziform, concave, front margins irregularly dentate, apex obtuse; midlobe recurved, oblong, a little widened to the apex, 0.6 by 0.4 cm, undulate, margins in apical part incurved, apex acute. Column 0.35 cm long, clinandrium denticulate, 3-lobulate, the lobules tooth-like, stigma small, rounded, deeply concave; column-foot at almost right angles to the ovary, c. 0.5 cm long, straight, apex truncate. Anther cucullate, quadrangular. Pollinia subtriangular, laterally compressed.
(after Smith, 1909).
Colours: Sepals and petals in basal third yellowish white, yellow in upper part, lip whitish, the midlobe pale yellowish with sparse dark purple dots, the lateral lobes with transverse purple spots, the spots confluent at the margin, keels pale yellowish; column pale yellowish green, below with purple dots, foot with dark purple spots. Pollinia yellow.
Habitat: Not recorded.
Flowering time in the wild: Not recorded.
Distribution: New Guinea (endemic).
Distribution in New Guinea: Papua (locality not recorded).
Cultivation: Warm growing epiphyte?.