Dendrobium hamiferum

Dendrobium hamiferum P.J.Cribb, Orchadian 6 (1981) 274.

Type: Reeve 400 (holo K; iso L, LAE).

A medium-sized epiphytic or lithophytic herb. Stems very slender cane-like, terete or slightly bilaterally compressed, somewhat dilated above, 35 to 110 cm long, 0.5 cm in diam., borne 1-2 cm apart on a creeping rhizome, clothed in leaf bases or sheaths, about 6- to 10-leaved towards apex. Leaves coriaceous, flat, suberect, distichous, narrowly oblong- to elliptic-lanceolate, obscurely unequally bilobed at apex, 6-8 by 1.6-2.5 cm, each with a basal sheath up to 4 cm long. Inflorescences terminal or subterminal, erect to spreading, about 17 cm long, laxly few-flowered; peduncle slender, terete; bracts triangular, acute, 2 mm long. Flowers subnutant; pedicel and ovary 2 cm long. Dorsal sepal porrect, linear-lanceolate, subacute, 2.5 by 0.5 cm, with side margins upturned; lateral sepals slightly falcate and incurved, oblong-lanceolate, subacute, 2.8 by 0.6 cm; mentum pointing backwards and slightly upcurved, hook-like, 6 mm long. Petals recurved or erect, linear, twisted up to 3 times, 2.8-3 by 0.2 cm. Lip elliptic in outline, 3-lobed in apical half, somewhat recurved at apex, 1.45 by 0.75 cm; side-lobes erect, narrowly oblong, rounded in front; midlobe ovate, acute, with undulate margins; callus of five fleshily thickened longitudinal ridges onto centre of midlobe. Column 4 mm long, with an erose apical margin and 2 acute stelidia; foot sinuous, 6 mm long, pubescent towards apex.
(after Cribb, 1986).

Colours: Sepals cream; petals cream with apices purplish on outer side; lip white, delicately marked with purple; ovary purplish-red.

Habitat: Epiphyte in montane forest and in forest on limestone hills, sometimes lithophytic. Altitude 0-1800 m.

Distribution: New Guinea.

New Guinea: Papua (Vogelkop Peninsula; Biak; Misool); Papua New Guinea (Highland Provinces).

Map: HAMIFMAP.JPG [Dendrobium hamiferum P.J.Cribb, distribution map, redrawn from P. Cribb, Kew Bull. 41 (1986) 650, map 5, with new record added.]

Notes: Dendrobium hamiferum is allied to Dendrobium crispilinguum with which it shares smallish flowers and a distinctive upcurved hook-like mentum. However, it may be readily distinguished from that species by its incurved sepals and small, less brightly coloured lip in which the midlobe margins are not crispate.

Of all species in the section, Dendrobium hamiferum has been found at the highest altitudes. In the western part of its area it occurs in the lowlands (van Bodegom 1973; Schuiteman & de Vogel, pers. obs.), mainly on limestone ridges, but there the climate is extremely wet.
(largely after Cribb, 1986).

Cultivation: Intermediate growing epiphyte.