Dendrobium trichostomum Rchb.f. ex Oliv., J. Linn. Soc., Bot. 15 (1875) 30.
Type: Meyer 1; 2 (New Guinea, Geelvinck Bay) (syn K).
Rhizome very short, roots elongated, filiform, flexuose, glabrous. Stems crowded, erect, slender, more or less quadrangular in cross-section, 20-40 cm by 0.3-0.5 mm, many-leaved. Leaf sheaths entirely covering the stem. Leaves erect-patent, lanceolate to lanceolate-oblong, 3.5-7.5 by 1.3-1.8 cm, apex acuminate, papyraceous. Inflorescences racemose, short, 6-12-flowered. Floral bracts lanceolate, much shorter than the pedicel and ovary, apex acuminate, glabrous, membranaceous. Pedicel and ovary 1.4 cm long, slender, terete. Flowers resupinated or not, c. 1.5 cm long. Dorsal sepal narrowly ligulate, 1.3 cm long, apex obtuse. Lateral sepals oblong, widened at the base, 1.3 cm long, apex subapiculate; mentum relatively short. Petals obliquely sublinear-spathulate, c. 1.2 cm long, apex obtuse. Lip concave, clawed, spathulate, 1.4 cm long, margins in apical half incurved, lacerate-fimbriate. Column short, clinandrium 3-dentate; column-foot elongated. Anther transversely subquadrate-cucullate.
(largely after Schlechter, 1912 - as Dendrobium oreogenum).
Colours: Flowers scarlet or purple-red.
Habitat: Epiphyte in hill forest. Altitude 500-900 m.
Flowering time in the wild: February, April, June-September.
Distribution: New Guinea (endemic).
Distribution in New Guinea: Papua (Manokwari and Nabire Regencies); Papua New Guinea (Sandaun and East Sepik Provinces).
Notes: Dendrobium trichostomum is a characteristic species because of the short mentum, the narrow sepals and petals, and the long-fringed upper margin of the lip.
Cultivation: Intermediate growing epiphyte.