Dendrobium angustipetalum J.J.Sm., Orchid. Ambon (1905) 59.
Type: Smith, J.J. s.n. (Ambon, Hoetoe Mortetoe); (Ternate Piek) (syn BO; isosyn L).
Rhizome short, roots elongated, filiform, flexuose, densely covered with tooth-like papillae. Stems crowded, erect to suberect, slender, 30-60 cm by 4-5 mm, in upper half or also lower down laxely several-leaved, not branched. Leaf sheaths entirely covering the stem. Leaves erect-patent, oblong-ligulate, 5-10 by 1.2-2.2 cm, apex unequally and obtusely bilobulate. Inflorescences laterally from the leaf-axils, racemose, erect-patent, 9 cm long, laxely 3-8-flowered. Floral bracts oblong, minute, much shorter than the pedicel and ovary, apex obtuse. Pedicel and ovary 1.5 cm long, slender, glabrous. Flowers resupinated, c. 1 cm across. Dorsal sepal very broadly semi-elliptic, 0.5 cm long, apex obtuse. Lateral sepals very broadly semi-elliptic, strongly oblique, much widened at the base, 0.5 cm long, apex obtuse; mentum oblongoid, 0.8 cm long, obtuse. Petals obliquely oblong-ligulate, at the base decurrent on the column-foot, 0.5 cm long, apex obtuse. Lip cuneate-subflabellate in outline, apical part widened, subreniform, 0.9 by 0.8 cm, base with an oblong appendage, the latter with two sharp keels on the inside, bilobed at the back, in front extended into two lanceolate acute wings which taper off above the middle of the lip, the lip in the centre with an ascending subulate acute tooth, apical margin subcrenulate, apex bilobate, minutely obtusely apiculate. Column short, clinandrium low; column-foot 0.8 cm long, pubescent at the broad base, narrowed to the uncinate-incurved apex. Anther subreniform-cucullate, glabrous.
(after Smith, 1905; partly after Schlechter, 1912 - as Dendrobium trachyrhizum).
Colours: Flower yellowish, apex of mentum violet-brownish.
Habitat: Epiphyte in lower montane forest. Altitude 1000-1100 m.
Flowering time in the wild: June, September.
Distribution: Moluccas, New Guinea.
Distribution in New Guinea: Papua New Guinea (Sandaun Province: Torricelli Mountains; Madang Province).
Cultivation: Intermediate growing epiphyte, keep in shade.