Dendrobium subquadratum J.J.Sm., Bull. Dép. Agric. Indes Néerl. 19 (1908) 20; Nova Guinea 8, 1 (1909) 65, t. 23, fig. 73.
Type: Versteeg 1391 (holo BO).
A pendent epiphytic herb. Pseudobulbs cylindrical, slightly dilated above, 6-30 by 0.3-0.5 cm, about 5-noded, yellow when dry, 2-leaved at apex. Leaves subcoriaceous, twisted at base to lie in one plane, narrowly elliptic or oblong-elliptic, acuminate, up to 17 by 2.5-3.7(-6.25) cm. Inflorescence erect or arcuate, up to 12 cm long, up to about 8-flowered; peduncle wiry, very slender; bracts ovate, acute, 3 mm long. Flowers rather fleshy; pedicel and ovary about 1.6 cm long. Dorsal sepal lanceolate, acuminate, 10-13 by 4-5 mm; lateral sepals obliquely ovate, acuminate, 11 by 8 mm; mentum conical, 6 mm long. Petals narrowly elliptic, acuminate, 9 by 2-2.5 mm. Lip long-clawed, recurved, 3-lobed above middle, 10-12 by 5-5.5 mm, side-lobes obliquely oblong, rounded in front; midlobe rugulose, conduplicate, longer than side-lobes, transversely oblong, truncate or apiculate; callus 3-ridged, running onto base of midlobe. Column 2.5 mm long, with an erose apical margin.
(after Cribb, 1983).
Colours: Flowers white, apparently later becoming yellowish.
Habitat: Epiphytic in hill forests. Altitude 300 to 800 m.
Flowering time in the wild: July.
Distribution: New Guinea.
Distribution in New Guinea: Papua (Jaya Wijaya Regency); Papua New Guinea (Sandaun Province).
Map: SUBQUMAP.JPG [Dendrobium subquadratum J.J.Sm., distribution map, redrawn from P. Cribb, Kew Bull. 38 (1983) 285, map 6.]
Notes: Dendrobium subquadratum is closest to Dendrobium euryanthum
but differs in its distinct flower colour, long-acuminate sepals and petals and narrower longer lip.
(after Cribb, 1983).
Cultivation: Warm growing epiphyte.