Diplocaulobium iboense (Schltr.) A.D.Hawkes, Lloydia 20 (1957) 128.
Basionym: Dendrobium iboense.
Rhizome short, roots elongated, filiform, flexuose, glabrous. Pseudobulbs crowded, 1-leaved, slender, slightly thickened to the base, ancipitous, 7-11 by 0.5 cm (at the base). Leaves linear, 4.5-7 by 0.3-0.5 cm, apex obtuse, strongly unequally bilobulate, subcoriaceous. Inflorescences arising in succession from the apex of the pseudobulb, 1-flowered, spathe laterally compressed, 1.5-1.7 cm long, acute. Pedicel and ovary 4 cm long, slender, glabrous. Flower resupinated, c. 8 cm across. Dorsal sepal lanceolate, 4 cm long, apex elongate-acuminate. Lateral sepals obliquely lanceolate, abruptly widened to the base, 4 cm long, apex elongate-acuminate; mentum oblongoid, 5 mm long, obtuse. Petals linear, filiform-elongated, c. 3.8 cm long. Lip 3-lobed in basal third, 0.9 by 0.45 cm (across lateral lobes), cuneate at the base, with two subparallel keels extending from the base of the lip to about halfway the midlobe, in apical half with a short third keel in between, lateral lobes falcate-oblong, about one third the length of the midlobe, obtuse; midlobe reniform with a ligulate claw, glabrous, apex broadly obtuse. Column short, clinandrium with minutely serrulate lobules; column-foot 0.5 cm long. Anther rectangular helmet-shaped, glabrous, in front broadly obtuse.
(after Schlechter, 1912).
Colours: Pseudobulbs straw-yellow. Sepals and petals pale yellow with brown tips, the lip with pale brown spots on the lateral lobes and with a white midlobe.
Habitat: Epiphyte in lower montane forest. Altitude 1000 to 2200 m.
Flowering time in the wild: January, May, July, September.
Distribution: New Guinea (endemic).
Distribution in New Guinea: Papua New Guinea (Western Highlands, Madang, and Morobe Provinces).
Notes: One of the species in which the narrow upper part of the pseudobulb is sharply laterally flattened.
Cultivation: Intermediate growing epiphyte.