Dendrobium tangerinum

Dendrobium tangerinum P.J.Cribb, Orchid Rev. 88 (1980) 144.

Type: Chadim CH 176 (holo K).

An epiphytic or rarely lithophytic herb. Stems cane-like, slightly swollen below, to 50 cm or more long. Leaves coriaceous, oblong or oblong-elliptic, obtuse, 7-9 by 2.5-3.2 cm, articulated below to coriaceous tubular sheaths 2-3 cm long. Inflorescences 1-several, up to 35 cm long, laxly few-15-flowered; bracts linear-lanceolate, acute or acuminate, 5-9 mm long. Flowers: pedicel and ovary 1.8-3 cm long. Dorsal sepal recurved-inrolled, oblong, obtuse, 2.3-2.5 by 0.6-0.7 cm, undulate on margins; lateral sepals recurved-in rolled, obliquely oblong-ovate, obtuse or slightly spiculate, 1.6-2.3 by 1-1.2 cm, with undulate margins; mentum slightly incurved, obliquely conical, 0.9-1 cm long. Petals erect, linear, acute, slightly dilated above, 3.3-4 by 0.4-0.5 cm, twisted (1-)2-3 times. Lip 3-lobed, elliptic in outline, 1.8-2.2 by 1.1-1.6 cm; side-lobes narrowly oblong, rounded in front, erose on margins; midlobe recurved, ovate, acute; callus of three low ridges terminating on base of midlobe. Column 5-7 mm long, denticulate or erose on apical margin.
(after Cribb, 1986).

Colours: Flowers orange-yellow to orange-red speckled with red-brown or maroon on sepals, with a lilac callus on the lip.

Habitat: Epiphyte in the canopy of tall rainforest trees and on trees along rivers. Mainly below 250 m above sea level, but some specimens have been found as high as 1250 m growing as lithophytes on exposed rocks.

Distribution: New Guinea.

Distribution in New Guinea: Papua New Guinea (Madang, Morobe & Milne Bay Districts).

Map: TANGEMAP.JPG [Dendrobium tangerinum P.J.Cribb, distribution map, redrawn from P. Cribb, Kew Bull. 41 (1986) 658, map 6, with new records added.]

Notes: Dendrobium tangerinum, which in the past has been misidentified as Dendrobium strepsiceros, is allied to Dendrobium cochliodes, but differs in its characteristic orange flowers and the incurved side lobes, short ovate, acute midlobe and low lilac callus of the lip. It differs from Dendrobium helix in that it lacks the conspicuous stelidia on the column of that species.
(largely after Cribb, 1986).

Cultivation: Warm to intermediate growing epiphyte. Requires strong light to flower well.