Dendrobium setosum

Dendrobium setosum Schltr., Repert. Spec. Nov. Regni Veg. Beih. 1 (1912) 618; 21 (1928) t. 208, fig. 786.

Type: Schlechter 17249 (holo B, lost; iso AD, AMES, BM, BO, G, K, L, NSW, S).

Rhizome elongated, creeping or climbing, to 50 cm long, stem-like, branching, rooting, roots elongated, filiform, flexuose, glabrous. Stems unbranched or sparsely branching, slightly laterally compressed, 5 mm wide, many-leaved. Leaf sheaths 0.5 cm wide, entirely covering the stem, densely transversely verruculose, deeply slit at the apex, margins with long stiff hairy-ciliate bristles. Leaves erect to erect-patent, linear-ligulate, 4-7.5 by 0.8-1.3 cm, apex unequally obtusely bilobulate, thick coriaceous. Inflorescences arising laterally from the stem, subsessile, 2-flowered; spathe short, semiorbicular, obtuse. Ovary 0.5 cm long, subsessile, glabrous. Flowers c. 1 cm across. Dorsal sepal oblong, 0.8 cm long, slightly keeled outside near the apex, apex obtuse. Lateral sepals obliquely oblong, widened at the base, 0.8 cm long, apex obtuse; mentum 0.5 cm long, obtuse. Petals obliquely ligulate-spathulate, c. 0.7 cm long, apex obtuse. Lip 3-lobed near the apex, broadly cuneate in outline, 0.7 by 1 cm, with a linear basal keel, sparsely dentate near its apex, which extends to beyond the middle; lateral lobes subfalcate-triangular, obtuse; midlobe much shorter, margins subundulate, apex obtusely bilobulate with a deep sinus between the lobules, apiculate. Column short, clinandrium 3-lobulate, the lateral lobules rounded, serrulate, the median triangular, acute; column-foot 0.5 cm long, concave. Anther rounded-cucullate, glabrous, in front slightly excised.
(after Schlechter, 1912).

Colours: Sepals and petals yellowish, lip and column-foot orange-yellow.

Habitat: Epiphyte in lower montane forest. Altitude 800-1200 m.

Flowering time in the wild: January, September.

Distribution: New Guinea (endemic).

Distribution in New Guinea: Papua New Guinea (Sandaun Province: Torricelli Mountains; Madang Province).

Map: SETOSMAP.JPG [Dendrobium setosum Schltr., distribution map.]

Notes: A very unusual species because of the long hairs fringing the leaf sheaths.

Cultivation: Intermediate growing epiphyte.