Diplocaulobium jadunae (Schltr.) A.D.Hawkes, Lloydia 20 (1957) 129.
Basionym: Dendrobium jadunae.
Rhizome to 15 cm long, creeping, roots elongated, filiform, flexuose, glabrous. Pseudobulbs closely spaced, 1-leaved, cylindrical-ovoid, 6-angled, with its base appressed to the rhizome, ascending, 0.8-1.3 by 0.5-0.8 cm. Leaves ligulate, 1.3-1.8 by 0.35-0.55 cm, apex obtuse, minutely bilobulate, coriaceous. Inflorescences arising in succession from the apex of the pseudobulb, 1-flowered; spathe laterally compressed, c. 5 mm long, obtuse. Pedicel and ovary 1.2 cm, slender, terete, glabrous. Flower resupinate, c. 2.5 cm across. Dorsal sepal lanceolate, narrowed to the apex, 1.2 cm long, apex obtuse. Lateral sepals falcate, oblique, widened at the base, 1.2 cm long, apex obtuse; mentum conical, c. 4.5 mm long, obtuse. Petals linear, subfalcate, somewhat narrowed in the middle, c. 1 cm long, apex subacute; glabrous. Lip 3-lobed in the middle, 1.3 by 0.4 cm, cuneate-ligulate at the base, with 3 keels, the lateral keels extending from the base to halfway the midlobe, converging in the middle, then diverging again, the central keel extending from the base of the midlobe to a little below its apex; lateral lobes short, triangular, acute; midlobe elliptic, c. 6.5 mm long, margins slightly undulate, subacuminate. Column short, glabrous, clinandrium 3-lobulate, the lateral lobules small, irregularly sparsely dentate, the median longer; column-foot c. 4.5 mm long. Anther globose-cucullate, rounded in front, glabrous.
(after Schlechter, 1912).
Colours: Flower white, keels of the lip yellow, margins of the lateral lobes red.
Habitat: Epiphyte in lowland hill forest. Altitude 10-300 m.
Flowering time in the wild: August to April. Flowers last 2-3 days (fide O'Byrne).
Distribution: Bismarck Archipelago, New Guinea (endemic).
Distribution in New Guinea: Papua New Guinea (Morobe, Central, and West New Britain Provinces).
Notes: May be recognised by the long, pointed midlobe of the lip, which is provided with three keels.
Cultivation: Warm growing epiphyte.