Dendrobium rariflorum J.J.Sm., Nova Guinea 14 (1929) 417, pl. 64, 70.
Type: Doorman 8 (holo BO).
Pseudobulbs clustered, slightly clavate, obtusely obscurely 7-angled , fleshy at the base, c. 3-noded, c. 8.5 cm long, 3.4 mm diam., 1-leafed. Leaf erect, linear-lanceolate, acute, shortly bidentate at apex, c. 3.4 by 0.5 cm, fleshy-coriaceous. Inflorescences 2, 1-2-flowered; peduncle filiform, longer than the leaf, c. 5-6 cm long, with several tubular sheaths above. Flowers, c. 1.75 cm broad, 1.85 cm high. Dorsal sepal subtriangular-oblong, obtuse, c. 13 by 4.8 mm; lateral sepals obliquely lanceolate, subacute, 17 by 7.7 mm; mentum conical, 6.25 mm long. Petals parallel, obliquely rhombic-spathulate, acute, c. 15 by 5.5 mm. Lip shortly adnate at base to column foot, 3-lobed, broadly rhombic when flattened, 17 by 12 mm; side-lobes erect, porrect, oblique-rhombic in front, slightly undulate, 4 mm long; midlobe porrect, 5-angled , obtusely apiculate, concave, c. 7 by 5.25 mm; callus of 3 parallel ridges, outer ridges spreading above into a free obliquely truncate quadrangular lamella, middle ridge slightly lower. Column very short, 1.75 mm long, with falcate-recurved, porrect auricles; anther transversely oval-reniform; column foot forming a sub-right angle with the ovary, incurved at apex, lightly 3-costate, 6 mm long.
(after Cribb, 1983).
Colours: Flowers ivory-white, dotted red-brown; lip white to pale green with several darker red-brown dots, streaked red-brown within.
Habitat: In montane forest on ridge, probably epiphytic. Altitude 1800 to 2200 m.
Flowering time in the wild: September.
Distribution: New Guinea.
Distribution in New Guinea: Papua (70 km north of Carstenz Mountains).
Map: RARIFMAP.JPG [Dendrobium rariflorum J.J.Sm., distribution map, redrawn from P. Cribb, Kew Bull. 38 (1983) 267, map 5.]
Notes: J.J. Smith compared this species to Dendrobium torricellense Schltr. from which it differs in having smaller one-leaved pseudobulbs and in the shape of its lip. He suggests that the type of Dendrobium rariflorum may be an immature specimen judging from the size of its vegetative parts.
(after Cribb, 1983).
Cultivation: Cool growing epiphyte.