Dendrobium laevifolium

Dendrobium laevifolium Stapf, Bot. Mag. 149 (1924) t. 9011.

Type: Colman cult. (Frost) s.n. (Louisiades, Rossel Isl.) (holo K) .

Tufted epiphyte, 2.5-18 cm high. Roots to c. 2 mm diameter. Rhizome short, to c. 0.5 cm. Pseudobulbs 0.7-4.5 by 0.2-l cm, to c. 6-noded, cylindrical, fusiform, flask-shaped or ovoid, crowded, apex 2-, occasionally 3-leaved (the third leaf then very small). Leaves (1.5-)5.5-14.5 by 0.5-2.5 cm, linear, oblong-lanceolate or elliptic, moderately thick, apex acute or subacute, mucronate, subpetiolate; sheaths tubular to c. 2 cm or more long, smooth, separating with age into loose spreading fibres. Inflorescences 1-2(-4)-flowered, mostly from leafless stems, terminal or from upper nodes, subsessile; bracts to 8 by 8 mm, rotundate to ovate-triangular, shortly acuminate or apiculate. Flowers 2-4.5 cm long, to 4.5 mm wide. Median sepal 12-25 by 5-11 mm elliptic-oblong to ovate-oblong, slightly keeled towards apiculate apex. Lateral sepals 20-30 by 5-l0 mm, oblong to ovate, gradually tapering towards acute or apiculate apex; basal fused part 4-7 mm long, tubular to narrow conical; mentum total length 8-20 mm, tip obtuse. Petals 12-19 by 6-11 mm obovate, rotundate or oblanceolate, apex obtuse apiculate. Lip to 21 by 3 mm c. 6 mm when expanded), oblanceolate, boat-shaped, papillose, margins upcurved, apex apiculate, with a crescent-shaped, shallow transverse callus c. 6 mm above the base. Column 4.5-5 by c. 2.5 mm foot 8-20 mm long, with a minute angular flap c. 2.5 mm from base; anther 1.5-2 mm wide; pollinia 1-1.5 mm long. Ovary obscurely triangular, angles rounded, shallowly 6-grooved; pedicel and ovary (8-)10-28 mm long. Fruit 28 by l0 mm, oblong-ovoid.
(after Reeve & Woods, 1989).

Colours: Leaves green or deep green, sometimes suffused purple below and at margin and mid-nerve; sheaths mid-green. Flower colour variable, cream, cream suffused pink, red, reddish purple or purple-pink, lip similarly coloured or paler, sometimes orange, margin yellow, pink or orange, column pale green or pink.

Habitat: Dendrobium laevifolium occurs in deep growths of lichen and moss on the trunks or slightly sloping branches of treelets a few feet above the mossy elfin forest bed almost constantly saturated with cold mist or light rain with brief bursts of very hot sunshine. Altitude 360 to 2135 m.

Flowering time in the wild: March, August, October.

Distribution: Louisiade Archipelago, Bougainville, Solomon Islands, Santa Cruz Islands.

Distribution in New Guinea: Papua New Guinea (Louisiade Archipelago: Tagula (Sudest) Island, Rossel Island).

Map: LAEVIMAP.JPG [Dendrobium laevifolium Stapf, distribution map, redrawn from T.M. Reeve & P.J.B. Woods, Notes Roy. Bot. Gard. Edinburgh 46 (1989) 286, map 8.]

Notes: Small plants of Dendrobium laevifolium could, at first glance, be mistaken for Dendrobium cuthbertsonii. The absence of warts on leaves and ovaries should ensure accurate identification.

Cultivation: Intermediate growing epiphyte, should be kept lightly shaded and moist at all times.