Dendrobium giriwoense J.J.Sm., Repert. Spec. Nov. Regni Veg. 12 (1913) 112; Nova Guinea 12, 4 (1916) 311, t. 113, fig. 204.
Type: Janowsky 141 (holo BO; iso L).
Rhizome short, roots thick. Stems crowded, in basal part thin, covered in scale-leaves, in cross-section elliptic, in upper part strongly laterally compressed, leafy, 55 cm by 3.3 mm, internodes in basal part to 1.8-2.3 cm long, in upper part 0.5-0.65 cm long. Leaf sheaths longer than the internodes, ancipitous, at apex excised and provided with a small tooth. Leaves widely patent, twisted at the base so as to lie in one plane, oblong-ovate, 2.3-4.3 by 0.9-1.2 cm, thin papyraceous, apex strongly unequally obtusely bilobulate. Inflorescences laterally from the stems; peduncle 0.2 cm long, 2-flowered, spathe 0.35 cm long. Pedicel and ovary 0.85 cm long. Flowers c. 1.5 cm across. Dorsal sepal 0.8 cm by 4 mm; mentum 0.4 cm long, truncate-rounded. Petals 0.75 cm by 3.6 mm. Lip 3-lobed, when flattened 0.7 by 0.73 cm; midlobe 0.26 by 0.4 cm. Column 0.3 cm long; column-foot 0.38 cm long, near the apex with a large subquadrangular callosity.
(after Smith, 1916).
Colours: Flower white.
Habitat: Epiphyte in lowland rainforest.
Flowering time in the wild: July.
Distribution: New Guinea (endemic).
Distribution in New Guinea: Papua (Nabire Regency: Giriwo River).
Map: GIRIWMAP.JPG [Dendrobium giriwoense J.J.Sm., distribution map.]
Notes: Dendrobium giriwoense belongs in the affinity of Dendrobium igneum and Dendrobium patentissimum, with which it agrees in habit. The midlobe of the lip is relatively much shorter in D. giriwoense than in the others.
Cultivation: Warm growing epiphyte.