Dendrobium falcatum J.J.Sm., Bull. Dép. Agric. Indes Néerl. 19 (1908) 17; Nova Guinea 8, 1 (1909) 72, t. 25, fig. 78; Nova Guinea 8, 3 (1911).
Type: Versteeg 1706 (holo BO).
Rhizome short. Stems crowded, patent, slender, lightly flexuose, elliptic in cross-section, c. 27-37.5 cm by 1.5 mm, many-leaved, internodes 1.5-1.7 cm long. Leaf sheaths a little longer than the internodes, transversely rhombic in cross-section, longitudinally ribbed, with a large triangular tooth 2-3 mm long opposite the leaf-blade. Leaves narrowly ovate-lanceolate, 3.5-4 by 0.95-1.1 cm, apex rather abruptly acuminate, obtuse, somewhat unequally acutely bidentate, keeled below. Inflorescences arising laterally from the stem, perforating two leaf-sheaths, very short, 2-flowered, spathe very short, laterally compressed. Ovary 0.25 cm long. Flowers c. 1.5 cm across. Dorsal sepal sigmoid, sublinear-oblong, 1.45 cm by 3.3 mm, outside concave, inside convex, outside near the apex verrucose, apex acute. Lateral sepals oblong-triangular, falcate, 1.3 cm by 4.8 mm, margins incurved, apex hood-like incurved; outside near the apex verrucose, concave; mentum saccate, broadly conical, c. 0.3 cm long, laterally compressed, obtuse. Petals spathulate, lightly falcate, 1.25 cm by 2.5 mm, at the base 3-, near the middle 5-nerved, apex incurved, acute. Lip subentire, oblong-rhombic, 5-angular, 0.73 by 0.4 cm, with a longitudinal crest which is widened on the midlobe and there provided with 3 rather obscure rows of warts or papillae, inside prominently transversely ribbed, in upper part lacerate, apex acuminate, acute. Column rather long, slightly curved, slightly constricted below the apex, 0.25 cm long, clinandrium 3-lobulate, the lateral lobules broad, denticulate, the median triangular; column-foot at right angles to the column proper, 0.3 cm long, apex incurved. Anther cucullate. Pollinia oblong, laterally compressed.
(after Smith, 1909 & 1911).
Colours: Sepals and petals white with purple dots, lip in the centre brown-orange, laterally densely striped with purple. Ovary pale yellow.
Habitat: Epiphyte in primary and secondary lowland and hill forest. Altitude 100 to 800 m.
Flowering time in the wild: April, July-September.
Distribution: New Guinea (endemic).
Distribution in New Guinea: Papua (Merauke and Jayapura Regencies); Papua New Guinea (Sandaun, Southern Highlands and Central Provinces).
Map: FALCAMAP.JPG [Dendrobium falcatum J.J.Sm., distribution map.]
Notes: In his initial description, J.J. Smith described the lip as being 3-lobed. Later, in 1911, after having examined living specimens, he stated that the lip is entire with crenate-lacerate margins in the apical part.
Cultivation: Warm growing epiphyte.