Dendrobium branderhorstii

Dendrobium branderhorstii J.J.Sm., Bull. Dép. Agric. Indes Néerl. 39 (1910) 8; Nova Guinea 8, 3 (1911) 561, t. 91D.

Type: Bogor cult. (Branderhorst 34); Bogor cult. (Exp. Lorentz, Rachmat 171) s.n. (syn BO).

Rhizome very short, roots elongated, rather thick, filiform, flexuose, glabrous. Stems crowded, pendulous, slender, at the base terete, slightly laterally compressed, somewhat widened towards the apex, 45-100 cm long, below 2.3-2.8 mm wide, above 4.5-5.8 mm wide, laxely many-leaved, internodes 1-2.8 cm long. Leaf sheaths entirely covering the stem, tubular, longer than the internodes, to 6 mm wide, opposite the leaf-blade with a triangular tooth. Leaves erect-patent, sublinear, 18.5-25 by 1-2.1 cm, apex strongly unequally bilobulate, coriaceous. Inflorescences lateral from the stem, short, peduncle 0.45-0.5 cm long, 2-flowered. Floral bracts lanceolate, a little shorter than the ovary, apex acute. Pedicel and ovary 0.9-2 cm long, clavate, squamulose. Flowers c. 2.5 cm across, very fleshy. Dorsal sepal oblong, 1.4-2.2 cm long, up to 1 cm wide, outside minutely squamulose-punctate, apex obtuse. Lateral sepals obliquely triangular-oblong, a little widened at the base, 1.4-2.2 cm long, up to 1 cm wide, apex obtuse; mentum very short and wide, strongly incurved, with an apical concavity. Petals obliquely oblong to spathulate-rhombic, 1.4-2 cm long, up to 1.2 cm wide, slightly twisted, strongly concave, outside in apical part deeply longitudinally grooved, apex obtuse. Lip 3-lobed near the middle, 1-1.4 cm long, up to 1.5 cm wide, broadly cuneate at the base, inside verrucose-rugose, 3-keeled, median keel low, flattened, extending to the base of the midlobe, lateral keels converging on the midlobe and continuing as a single median keel; lateral lobes erect, obliquely triangular, obtuse, interior margin erose; midlobe much extending beyond the lateral lobes, to 0.7 by 0.63 cm, subquadrate-rounded, apiculate. Column up to 0.8 cm long, clinandrium with denticulate-serrulate to lacerate margins; stigma suborbicular, column-foot at an acute angle with the ovary, strongly incurved, up to 1 cm long, in front with a longitudinally grooved callus which appears to be composed of several fused horizontal plates with lacerate margins. Anther subquadrate-cucullate, c. 2.3 mm wide, glabrous, in front sulcate. Pollinia narrowly linear-oblong.
(after Schlechter, 1905, and Smith, 1911).

Colours: Flower light yellow, callus on the column-foot orange-yellow.

Habitat: Epiphyte in lowland forest. Altitude 0 to 800 m.

Flowering time in the wild: January, June, September, October, November.

Distribution: Bismarck Archipelago, New Guinea.

Distribution in New Guinea: Papua (Merauke and Jayapura Regencies); Papua New Guinea (Gulf, Southern Highlands, Madang, Morobe, Central, Oro, West New Britain, and New Ireland Provinces).

Map: BRANDMAP.JPG [Dendrobium branderhorstii J.J.Sm., distribution map.]

Notes: As the name Dendrobium angraecifolium had already been used for a different species by Finet, the name Dendrobium branderhorstii takes precedence for this common species.

Cultivation: Warm growing epiphyte.