Dendrobium affine

Dendrobium affine (Decne.) Steud. Nomencl. Bot., ed. 2, (1841) 489.

Basionym: Onychium affine.

Rhizome short. Stems crowded, erect, clavate, thickened at the base, 30-37 cm long, 12-29 mm wide in the middle, above the base 5.5-6 mm wide, becoming grooved with age, in upper part 6-9-leaved, internodes to 4-4.5 cm long, shorter in upper part. Leaf sheaths tubular, ribbed. Leaves patent, narrowly lanceolate, 9.5-19 by 2-3 cm, apex obliquely acute to unequally acutely 2-dentate, carnose, c. 5-nerved, the median nerve slightly prominent below, the others grooved on both sides. Inflorescences arising from the upper internodes of the stem, racemose, erect, curved, 35-54 cm long; peduncle 23-28 cm by 1.75-2.5 mm, terete, peduncle-scales several, tubular, shortly acuminate; rachis 12-26 cm long, laxely 12-25-flowered. Floral bracts lanceolate-triangular, 0.3-0.6 cm long, apex sharply acuminate, concave. Pedicel 2 cm long; ovary 0.6-0.7 cm long, 6-grooved, curved. Flowers 3 cm across. Dorsal sepal narrowly oblong, 1.75-2 cm by 5.7-6.3 mm, apex abruptly shortly acuminate. Lateral sepals obliquely oblong, lightly falcate, a little widened to the base, 1.75-1.9 cm by 7-9 mm, apex abruptly acuminate; mentum spur-like. Petals much broader than the sepals, rhombic-obovate, 2-2.35 cm by 13.5 mm, cuneate-clawed at the base, apex broadly obtuse to rounded, apiculate. Lip 3-lobed above the middle, 1.5-1.75 by 1-1.1 cm, with 3 low keels extending to below the middle of the midlobe, on and also between the keels with muricate-scaly hairs; lateral lobes erect, incurved, obliquely ovate-triangular, clasping the column and extending beyond it, slightly undulate, broadly obtuse; midlobe porrect, linear-oblong, 0.75-0.85 by 0.4-0.45 cm, obtuse, shortly acuminate. Column thick, 0.25-0.38 cm long, papillose, clinandrium 5-dentate, stigma large, short, broadly subobovate; column-foot at right angles to the ovary, 0.57-0.75 cm long, almost straight, consisting of two parts, the basal part broad, flat, quadrangular, 0.17-0.3 cm long, grooved, convex, the upper part spur-like, straight, oblong, 0.4-0.45 cm long, laterally compressed, apical margin recurved, inside with two large fleshy calli separated by a deep groove. Anther cucullate, dorsally emarginate, apex truncate, ciliolate, papillose. Pollinia narrowly obliquely oblong-pyriform.
(after Smith, 1909).

Colours: Flower pure white, the keels on the lip yellowish in apical party and throughout their length with pale violet spots. Column white. Pollinia golden yellow.

Habitat: Lowland epiphyte.

Flowering time in the wild: Not recorded.

Distribution: Lesser Sunda Islands, Moluccas, New Guinea, Australia.

Distribution in New Guinea: Papua (Merauke Regency); Papua New Guinea (Gulf Province, fide Millar).

Notes: A more humble relative of the glamorous Dendrobium bigibbum.

Cultivation: Warm growing epiphyte, requires much light and a dry resting period.