Dendrobium igneum J.J.Sm., Bull. Dép. Agric. Indes Néerl. 19 (1908) 17; Nova Guinea 8, 1 (1909) 73, t. 25, fig. 79.
Type: Versteeg 1260 (syn BO; iso L); 1572 (syn BO).
Rhizome short (roots thick). Stems crowded, erect to patent, compressed, elliptic in cross-section, 30-40 cm long, densely many-leaved, internodes 0.5-0.7 cm long. Leaf sheaths tubular, twice as long as the internodes, compressed. Leaves widely patent, ovate-oblong, 1.6-3.2 by 0.75-1.3 cm, base half-twisted, apex obtuse, unequally bilobed, the lobes rounded; with 5-7 main nerves. Inflorescences arising laterally from the stem, perforating two leaf-sheaths, very short, 2-flowered, spathe laterally compressed, 0.3-0.4 cm long, rounded. Pedicel 1.6-1.75 cm long; ovary 0.3-0.35 cm long, 6-ribbed. Flowers c. 3 cm across. Dorsal sepal oblong, 1.35-1.5 cm by 6.7-7 mm, 7-nerved, apex obtuse. Lateral sepals obliquely oblong-triangular, 1.4-1.7 cm by 10 mm, apex obtuse, apiculate to subacute; concave; mentum broad, c. 0.7 cm long, obtuse, dorsally compressed. Petals obovate, claw-like narrowed to the base, 1.45-1.7 cm by 7.4-9 mm, at the base 3-nerved, apex broadly obtuse. Lip 3-lobed near the middle, 1.35-1.5 by 0.77-0.8 cm, with a longitudinal basal keel extending to the base of the midlobe, near the apex with a subulate backwards-pointing tooth, midlobe inside transversely rugose; lateral lobes erect, triangular, more or less falcate-incurved, erose to finely laciniate, apex acute; midlobe much larger, at right angles to the base of the lip, broadly cuneate, 0.65-0.7 by 0.7-0.76 cm, apex lightly rounded, weakly erose. Column broad, 0.45 cm long, clinandrium 3-lobulate, dentate, the lateral lobules narrow, the median filiform; stigma large, transverse, trapeziform; rostellum absent (always?); column-foot at an acute angle to the ovary, 0.66-0.7 cm long, broadly linear, incurved, at the apex with two low swellings. Anther cucullate, constricted below the apex, in front broad.
(after Smith, 1909).
Colours: Flower orange inside, outside whitish.
Habitat: Epiphyte in lowland forest, hill forest on limestone, and in Pandanus and Metroxylon swamps.
Flowering time in the wild: February, June, August.
Distribution: New Guinea (endemic).
Distribution in New Guinea: Papua (Sorong, Puncak Jaya, and Merauke Regencies); Papua New Guinea (?Central Province).
Map: IGNEUMAP.JPG [Dendrobium igneum J.J.Sm., distribution map.]
Notes: The neat habit with dense, regular foliage, and the relatively large, glistening orange flowers make Dendrobium igneum one of the prettiest members of sect. Grastidium.
Cultivation: Warm growing epiphyte, keep in shade.