Dendrobium macrogenion Schltr., Repert. Spec. Nov. Regni Veg. Beih. 1 (1912) 513; 21 (1923) t. 174, fig. 649.
Type: Schlechter 19600 (holo B, lost).
Rhizome very short, roots elongated, filiform, flexuose, glabrous. Stems crowded, patent, slender, up to 60 cm by 5-7 mm, densely many-leaved; unbranched. Leaf sheaths entirely covering the stem. Leaves patent-erect, lanceolate, 7-8.5 by 1.3-1.6 cm, apex acute or acuminate, thin-textured. Inflorescences lateral from the stem, racemose, short, densely several-flowered. Floral bracts ovate, much shorter than the pedicel and ovary, apex shortly acuminate. Pedicel and ovary 3 cm long, slender, glabrous. Flowers resupinated or not, c. 3 cm long. Dorsal sepal broadly ovate, 0.8 cm long, apex obtuse or minutely apiculate. Lateral sepals obliquely broadly ovate, very much widened at the base, 0.8 cm long, apex obtuse or minutely apiculate; mentum conico-cylindrical, c. 2.5 cm long, slightly curved, obtuse, in front closed in basal half. Petals obliquely elliptic-ligulate, 0.8 cm long, apex obtuse. Lip strongly concave, from a linear-ligulate base gradually becoming subrhombic-cucullate, 3.2 by 0.7 cm, near the middle with a low transverse lamella, apical margin fimbriate-dentate, plicate; apex hood-like. Column short, clinandrium 3-lobulate, the lateral lobules semirhombic, the median tooth-like; column-foot concave, 2.5 cm long, near the apex with an elliptic concavity. Anther broadly quadrate-cucullate, at the back retuse, in front truncate, minutely papillose.
(after Schlechter, 1912).
Colours: Flowers brilliant red with darker veins; the lip whitish with violet veins; column violet at the top, anther violet with a white tip.
Habitat: Epiphyte in lower montane forest. Altitude 1200 m.
Flowering time in the wild: May.
Distribution: New Guinea (endemic).
Distribution in New Guinea: Papua New Guinea (Morobe Province: Dischore Mountains).
Notes: Probably not distinct from Dendrobium lawesii.
Cultivation: Intermediate growing epiphyte.