Diplocaulobium inauditum (Rchb.f.) Kraenzl., in Engl., Pflanzenr. IV. 50. II. B. 21 (1910) 341.
Basionym: Dendrobium inauditum.
Pseudobulbs 1-leaved, thick fusiform at the base, there elliptic in cross-section, the upper part very slender, bilaterally flattened, c. 4 times as long, total 15-22 cm long, near the base 2.5 cm wide and 1 cm thick. Leaves elliptic, 10 by 4 cm, rather thick, apex obtuse to subacute. Inflorescences 1-flowered. Pedicel and ovary elongated. Flower c. 8 cm across. Sepals lanceolate, 4-4.5 cm by 3-4 mm, apex caudate. Petals almost equal to the sepals. Lip 3-lobed, 1.5 cm long, with 2 parallel keels between the lateral lobes; lateral lobes subquadrate, 6-7 mm long; midlobe ligulate (appears narrowly ovate in the illustration - A.S. & E. de V.), margins undulate, apex abruptly acuminate.
(after Kraenzlin, 1910 - measurements calculated by Kraenzlin, based on Reichenbach's plate in Lindenia).
Colours: Sepals and petals sulphur yellow, lip pale yellowish with brownish veines and dots, the keels brownish.
Habitat: Not known.
Flowering time in the wild: Not known.
Distribution: ?Bismarck Archipelago.
Distribution in New Guinea: Papua New Guinea (?New Ireland).
Notes: Kraenzlin added his own Dendrobium pleurothalloides to the synonymy of Diplocaulobium inauditum, which is certainly not justified. It is unclear if his records, which are all from New Ireland, include properly identified specimens of D. inauditum, or only D. pleurothalloides. The origin of D. inauditum was originally given as Polynesia, in Lindenia as Papuasian Islands.