Dendrobium acuiferum Ormerod, Checkl. Papuasian Orch. (2017) 164, 466 (fig.).
Type: Reeve 802 (holo AMES; iso BISH, BO, CANB, E, K, L, LAE, NSW, UPNG).
Terrestrials. Rhizome not seen. Roots along the stem few, short, 0.7-1.2 by up to 0.07 cm. Stem (fragment) slender, elliptic in section, laxly leafy, to 39.5 by 0.15-0.22 cm; exposed part of internodes 0.3-2.5 cm long. Leaves narrowly lanceolate, thin, , 3.9-6.7 by 0.33-0.5 cm; leaf sheaths tubular, smooth, striate, minutely transversely rugulose, especially near the apex, 1.2-2.9 cm long, its apex with a triangular, acute, 0.2-0.3 cm long lobe; apex with 2 minute obtuse lobes differing to 0.05-0.07 cm in length. lnflorescence 2-flowered; peduncle 0.4-05 cm long; basal inflorescence scales: 1st transversely oblong, 0.1-0.25 by 0.25-0.33 cm, 2nd curved upwards, oblong, 0.35-0.6 by 0.2-0.25 cm, with obtuse apex; 3rd oblong, very thin and papery, 0.45 by 0.25 cm, with acute apex. Pedicel and ovary club-shaped, 0.9 cm long. Median sepal linear-lanceolate, 3.7 by 0.4 cm; apex acute; 9 nerved. Lateral sepals in lower third obliquely ovate-lanceolate, above linear, 3.7 by 0.8 cm; apex acute; 7-nerved; mentum rounded, 0.7 cm long, apically curved. Petals linear- lanceolate, 3.6 by, 0.2 cm; apex acute; 5-nerved. Lip 3-lobed, 1.28 cm long; hypochile 0.45 by 0.6 cm in the middle, its lateral lobes shortly triangular, subfalcate, 0.1 cm long (along inner margin 0.12 cm long), keels 5, the outer 4 very short and at the very base of the lip, the median keel plate-like, terminating on the base of the epichile in an oblique, triangular, acute point, in front of this with a short, thin plate-like keel with 2 erect, subulate projections, hypochile surface with few irregular laminate ridges or projections, with acute apex; epichile ovate, margins irregularly dentate-laciniate, median with an ovate-elliptic patch of pubescence, 0.83 by, 0.6 cm, with acute apex. Column obliquely conical, 0.36 cm long (without the anther), its front margin on each side with a tiny obtuse lobule; column foot gently incurved, 0.6 cm long, in front with 2 swollen ridges, the top 0.2 cm is excavate.
(After Ormerod, 2017)