Diplocaulobium arachnoideum (Schltr.) Carr, Bull. Misc. Inform. Kew (1934) 381.
Basionym: Dendrobium arachnoideum.
Rhizome very short, roots elongated, filiform, flexuose, glabrous. Pseudobulbs crowded, 1-leaved, slender, to the base obclavate-swollen, 7.5-9.5 by 0.6-1 (at the base) to 0.15-0.2 cm (near the apex). Leaves linear, 8.5-11.5 by 0.4-0.5 cm, apex obtuse, unequally bilobulate, subcoriaceous. Inflorescences arising in succession from the apex of the pseudobulb, 1-flowered, spathe laterally compressed, c. 1.5 cm long, subacute. Floral bract deltoid, minute. Pedicel and ovary 3.5-4 cm long, slender, glabrous. Flower resupinated, c. 9 cm wide. Dorsal sepal lanceolate, narrowing to the elongated apex, 5 cm long. Lateral sepals obliquely lanceolate, narrowing to the elongated apex, widened to the base, 5 cm long; mentum c. 0.6 cm long, obtuse. Petals obliquely narrowly lanceolate, narrowing to the elongated apex, c. 4.8 cm long. Lip weakly 3-lobed in the middle, subpandurate in outline, 1.3 by 0.4 cm, with two parallel keels extending from the base to the middle, in front of the keels with an oblong farinose-puberulous callus; lateral lobes hardly developed, broadly obtuse; midlobe ligulate, at the base slightly narrowed and with somewhat undulate margins, obtuse. Column short, clinandrium 3-lobulate, the median lobule acute, triangular, the laterals shorter, truncate; column-foot c. 0.6 cm long. Anther subreniform-cucullate, glabrous, in front truncate.
(after Schlechter, 1912).
Colours: Flowers red (late anthesis?), the lip white with red markings in basal half, in upper half pinkish red with a yellow callus.
Habitat: Epiphyte in lower montane forest. Altitude 1300 m.
Flowering time in the wild: June.
Distribution: New Guinea (endemic).
Distribution in New Guinea: Papua New Guinea (Morobe Province: Dischore Mountains).
Cultivation: Intermediate growing epiphyte.