Dendrobium macrifolium J.J.Sm., Nova Guinea 18 (1935) 50, pl. 10, 30.
Type: Docters van Leeuwen 10443 (holo BO).
Rhizome short. Stems crowded, slender, unbranched, terete, flexuose, 28 cm by 1.6 mm, internodes 1.2-1.6 ('0.6') cm long. Leaves patent at the base, recurved, linear, constricted below the apex, 2.3-3.3 by 0.16 cm, when flattened c. 0.2 cm wide, rigid, channelled, convex below, apex acute to narrowly obtuse. Pedicel 0.25 cm long; ovary 0.24 cm long. Flowers c. 0.68 cm long. Dorsal sepal 0.36 cm by 2 mm; mentum 0.36 cm long, truncate, subretuse. Petals 0.35 cm by 1.5 mm. Lip when flattened 0.68 by 0.24 cm, base adnate to the column-foot for 0.18 cm. Column 0.18 cm long; column-foot 0.33 cm long.
(after Smith, 1935).
Colours: Sepals and petals light green, lip darker bright green.
Habitat: Epiphyte in rainforest. Altitude 250 m.
Flowering time in the wild: September.
Distribution: New Guinea (endemic).
Distribution in New Guinea: Papua (Paniai Regency).
Notes: Dendrobium macrifolium is a distinctive member of sect. Pedilonum because of its very narrow leaves. The green flowers are among the smallest in the section.
Cultivation: Warm growing epiphyte.