Dendrobium macrum Schltr., in K.Schum. & Lauterb., Nachtr. Fl. Deutsch. Schutzgeb. Südsee (1905) 174; Repert. Spec. Nov. Regni Veg. Beih. 21 (1928) t. 211, fig. 796.
Type: Schlechter 14551 (holo B, lost).
Rhizome very short, roots elongated, filiform, flexuose, glabrous. Stems crowded, erect, terete, unbranched, slender, 15-20 cm long, many-leaved. Leaves erect-patent, narrowly linear, 3-4 by 0.15-0.2 cm, apex minutely emarginate, papyraceous. Inflorescences arising laterally from the stem, 1-flowered, sessile. Ovary 0.3 cm long, cylindrical, glabrous. Floral bract minute, ovate, acuminate. Flower not resupinated, c. 0.6 cm across. Dorsal sepal ovate-oblong, 0.4 cm long, apex obtuse. Lateral sepals strongly obliquely ovate-oblong, much widened at the base, 0.4 cm long, apex obtuse. Petals obliquely linear-lanceolate, 0.4 cm long, apex acute. Lip 3-lobed above the middle, 0.6 by ; lateral lobes short, obtuse; midlobe much larger, very broadly ovate, shortly acuminate. Column short, clinandrium crenulate with a median dorsal tooth; column-foot large. Anther subquadrate, dorsally excised.
(after Schlechter, 1905).
Colours: Sepals and petals white, column and lower half of lip speckled with red.
Habitat: Epiphyte in hill and montane forest. Altitude 600 to 1500 m.
Flowering time in the wild: February, April, June, September.
Distribution: New Guinea (endemic).
Distribution in New Guinea: Papua New Guinea (Enga and Madang Provinces).
Cultivation: Intermediate growing epiphyte.