Dendrobium clausum Schltr., Repert. Spec. Nov. Regni Veg. Beih. 1 (1912) 607; 21 (1928) t. 204, fig. 769.
Type: Schlechter 18168 (holo B, lost; iso AMES, BO, E, G, K, L 2x, NSW).
Rhizome very short, roots elongated, filiform, flexuose, glabrous. Stems crowded, erect-patent, unbranched, slightly laterally compressed, 30-40 cm by 4-5 mm, densely many-leaved. Leaves patent, elliptic-ligulate, 4.5-7 by 1.2-2.1 cm, apex oblique, unequally subacutely bilobulate. Inflorescences arising seemingly from the leaf axils, short; peduncle very short; 2-flowered; spathe laterally compressed, semioblong, obtuse. Pedicel and ovary 1.6 cm long, slender, glabrous. Flowers c. 1 cm across, often cleistogamous. Dorsal sepal oblong, 0.9 cm long, apex obtuse. Lateral sepals obliquely oblong, a little widened at the base, 0.9 cm long, apex obtuse; mentum short, obtuse. Petals obliquely oblong, a little shorter than the sepals, apex obtuse. Lip 3-lobed near the middle, 0.65 by 0.4 cm, oblong-cuneate at the base, inside especially in the lower half sparsely transversely rugulose, with a narrow keel extending to near the apex of the midlobe, just below the apex of the midlobe with a triangular thickening; lateral lobes small, obliquely quadrate, in front subtruncate, sparsely toothed; midlobe large, orbicular, 0.43 cm wide, broadly obtuse. Column short, rather thick, clinandrium 3-lobulate, the lateral lobules triangular, acute, the median about as long, tooth-like; column-foot incurved. Anther quadrate-cucullate, in front truncate, glabrous.
(after Schlechter, 1912).
Colours: Flower light yellow, lip in front white, column-foot with an orange-yellow spot.
Habitat: Epiphyte in lower montane forest. Altitude 1200 m.
Flowering time in the wild: September.
Distribution: New Guinea (endemic).
Distribution in New Guinea: Papua New Guinea (Madang Province: Finisterre Mountains).
Map: CLAUSMAP.JPG [Dendrobium clausum Schltr., distribution map.]
Cultivation: Intermediate growing epiphyte.