Dendrobium rarum Schltr., Repert. Spec. Nov. Regni Veg. Beih. 1 (1912) 504; 21 (1923) t. 171, fig. 637.
Type: Schlechter 18252; 19512 (B, lost).
Rhizome very short, roots elongated, filiform, flexuose, glabrous. Pseudobulbs crowded, many-leaved, slender, terete, slightly curved or almost straight, 42 by 0.3-0.4 cm. Leaf sheaths entirely covering the pseudobulbs. Leaves linear, 7.5-11 by 0.35-0.45 cm, apex acute. Inflorescences lateral, racemose, patent, 3 cm long; peduncle 0.8 cm long, slender; rachis c. 2 cm long, densely many-flowered. Floral bracts ovate, small, much shorter than the pedicel and ovary, apex shortly acuminate, apiculate. Pedicel and ovary 1.3 cm long, slender, clavate, glabrous. Flowers c. 1 cm long. Dorsal sepal elliptic, 0.5 cm long, apex obtuse, minutely apiculate; outside sparsely papillose-punctate. Lateral sepals obliquely elliptic, widened at the base, 0.5 cm long, connate in front in basal part, apex obtuse, minutely apiculate; mentum conical, c. 5 mm long, obtuse. Petals obliquely lanceolate-ligulate, 0.4 cm long, margins in upper half minutely serrulate, apex subacute. Lip oblong, with a basal claw which is adnate to the column-foot, 0.9 by 0.33 cm, claw 2.5 mm long, blade at the base with a short keel which divides into two arms in front, the arms decurrent on the basal margins of the blade, apex shortly and obtusely acuminate, serrulate-ciliolate. Column short, clinandrium 3-lobulate, the lateral lobules short, rounded in front, acute at the back, the median tooth like, slightly longer; column-foot c. 5 mm long. Anther rhomboid-cucullate, emarginate at the back, provided with an obtuse hump, in front truncate and minutely papillose-punctate.
(after Schlechter, 1912).
Colours: Flowers pinkish red with white tips.
Habitat: Epiphyte in lower montane forest. Altitude 1200-1600 m.
Flowering time in the wild: March, May, August, September.
Distribution: New Guinea (endemic).
Distribution in New Guinea: Papua New Guinea (Enga, Madang, and Morobe Provinces).
Cultivation: Intermediate growing epiphyte.