Diplocaulobium xanthocaulon (Schltr.) A.D.Hawkes, Lloydia 20 (1957) 130.
Basionym: Dendrobium xanthocaulon.
Rhizome very short, roots elongated, filiform, flexuose, glabrous. Pseudobulbs crowded, 1-leaved, slender, thickened to the base, ancipitous, 15-26 by 0.7-1.2 cm (at the base). Leaves ligulate, 14-18 by 2.3-3 cm, base cuneate, apex subacute, coriaceous. Inflorescences arising in succession from the apex of the pseudobulb, 1-flowered; spathe laterally compressed, c. 2.5 cm long, acute to acuminate. Pedicel and ovary 11 cm long, slender, glabrous. Flower resupinated, 7-8 cm across. Dorsal sepal narrowly lanceolate, narrowing to the elongated apex, 3-4 cm long. Lateral sepals obliquely narrowly lanceolate, narrowing to the elongated apex, abruptly widened at the base, 3-4 cm long, mentum 4 mm long, obtuse. Petals obliquely linear-lanceolate, narrowing to the elongated apex, c. 3-3.8 cm long. Lip 3-lobed in basal fourth, 1.4 by 0.43 cm, cuneate at the base, with two parallel keels extending from the base of the lip to the base of the blade of the midlobe; lateral lobes very short, obliquely triangular, obtuse; midlobe reniform with an obcuneate-ligulate claw, the blade c. 4.3 by 5 mm, margins of the blade undulate-crenate, apex apiculate. Column short, clinandrium 3-lobulate, the median lobule tooth-like, acute, the laterals obtuse; column-foot c. 0.4 cm long. Anther cucullate, glabrous.
(after Schlechter, 1912).
Colours: Sepals and petals pale yellow with white tips, the lip golden yellow with red dots and red tips to the lateral lobes; column-foot provided with a red spot.
Habitat: Epiphyte in hill forest. Altitude 300 m.
Flowering time in the wild: April, December.
Distribution: New Guinea (endemic).
Distribution in New Guinea: Papua New Guinea (Eastern Highlands and Morobe Provinces).
Notes: Closely related to Diplocaulobium compressicolle.
Cultivation: Warm growing epiphyte.