Dendrobium horstii J.J.Sm., Icon. Bogor. 3 (1906) 23, t. 210.
Type: Bogor cult. (Horst) s.n. (holo BO).
Rhizome short. Stems crowded, elongated, in cross-section elliptic, rigid, 68 cm by 8.5 mm, internodes 1.75-2.5 cm long. Leaves patent, lanceolate, 14 by 4.3 cm, fleshy coriaceous, base amplexicaul, apex unequally bilobulate. Inflorescences laterally from the stems, very short; peduncle 0.35 cm long, 2-flowered. Pedicel 2.4 cm long; ovary 1.3 cm long. Flowers c. 2.5 cm across, very fleshy. Dorsal sepal 2 cm by 9 mm. Lateral sepals 1.8 cm by 1.1 mm, mentum c. 0.55 cm long. Petals 1.95 cm by 9 mm. Lip 3-lobed, when flattened 1.1 by 0.72 cm; midlobe 0.5 by 0.7 cm. Column 0.6 cm long; column-foot 0.55 by 0.5 cm.
(after Smith, 1907).
Colours: Sepals and petals orange-yellow, lateral lobes of the lip dark violet, midlobe pale yellow-orange, column white, anther yellowish white.
Habitat: Epiphyte in lowland rainforest.
Flowering time in the wild: Not known.
Distribution: New Guinea (endemic).
Distribution in New Guinea: Papua (Manokwari and Merauke Regencies).
Notes: Probably a lowland species.
Cultivation: Warm growing epiphyte.