Dendrochilum longifolium

Dendrochilum longifolium Rchb.f., Bonplandia 4 (1856) 329

Type: Stange cult. (Schiller) s.n., herb. Reichenbach f. 4908 (holo W)

Roots 0.15 cm diam., glabrous, not or sparsely branching. Rhizome short. Pseudobulbs 0.3-0.5 cm apart, cylindrical, fusiform to ovoid, 3-8.5 by 0.6-1.8 cm, initially covered with 4-6 nearly perfectly tubular, rounded to acute cataphylls which soon disintegrate into persistent fibres. Leaf petiolate; petiole channelled, 1.5-7 cm long; blade lanceolate, acute, 8-25 by 2.4-5 cm , thin-textured with 7-9 distinct (and many indistinct) nerves. Inflorescence synanthous, suberect, peduncle slender, terete, 11.5-24.0 cm long, (sub)glabrous; rachis more or less pendent with distichously alternating flowers, moderately dense, 40-50-flowered with internodes of c. 0.30 cm, somewhat furrowed, c. 14 cm long, (sub)glabrous, basally with 1-5 appressed, non-floriferous bract(s). Floral bracts (semi-orbicular-)ovate to broadly oblong when spread, persistent, acuminate, 0.42-0.8 by 0.4-0.49 cm, quite entire, 9-10-nerved, sparsely and finely setose. Flowering starting from the basal part of the rachis. Flower widely opening, c. 0.8 cm across. Median sepal (oblong-)lanceolate, acuminate, 0.66-0.79 by 0.21-0.26 cm, quite entire, 3-veined, glabrous; lateral sepals lanceolate, usually widest in the proximal part, acuminate, 0.63-0.82 by 0.21-0.28 cm, quite entire, 3-veined, glabrous; petals obliquely lanceolate, acuminate to subacute, 0.58-0.69 by 0.19-0.23 cm , quite entire to very slightly irregular along the margin, 3-veined, glabrous. Lip rather mobile, more or less pendent, sessile, 3-lobed, 0.45-0.67 by 0.27-0.39 cm, 3-veined, glabrous and smooth, with two proximally interconnected keels running from the base to near the middle of the mid-lobe, between the keels with a longitudinal groove extending almost to the lip-apex; margin slightly irregular along the mid-lobe, otherwise quite entire; disc flat; side lobes porrect to slightly spreading, obliquely linear-triangular, acute to acuminate, distinctly shorter than the mid-lobe; mid-lobe gradually recurved, broadly (orbicular-)elliptic to obovate, acuminate. Column suberect, strongly incurved, semiterete, 0.29-0.4 cm long, smooth, at the apex prolonged into a rounded, finely (dentate-)crenate wing which distinctly exceeds the anther; foot short; stelidia appearing from the middle of the column proper, suberect to more or less porrect, linear(-triangular), somewhat falcate, unequally emarginate to very obliquely acuminate, distinctly shorter than the column proper (approximately reaching the level of the anther), smooth. Anther ovate-triangular to reniform in upper view, acute to acuminate in front, with a distinct, conical wart on top. Pollinia obliquely (ellipsoid-)pyriform with short caudicles. Rostellum somewhat protruding, ovate-triangular; fertile stigma obtriangular semi-orbicular to subquadrate in outline, concave with slightly elevated margins. Ovary with pedicel semifusiform-conical to nearly terete, not twisted, 0.31-0.52 cm long, (sub-)glabrous. Fruit not seen. (After Pedersen, 1997, and O’Byrne, 1994).

Colours: Pseudobulbs green to orange, the latter especially when growing in exposed positions. Sepals and petals translucent green to greenish yellow. Lip yellow, green or brownish, usually with a brown mid-lobe, the keels and often the central groove bright green.

Habitat: Epiphyte in lowland to montane forest in shaded to exposed positions (upper altitudinal limit dubious). Altitude 250-3000 m.

Flowering time in the wild: January, February, March, April, May, June, July, September, October, December.

Distribution: Malesia (Peninsular Malaysia, Singapore, Sumatra, Java, Borneo, ?Sulawesi, ?Lesser Sunda Islands, Moluccas, New Guinea, The Philippines), Burma.

Distribution in New Guinea: Papua (Indonesia); Papua New Guinea. See map: 215-178M.JPG

Cultivation: Warm to cool growing epiphyte.

Note: One of the most commonly encountered orchids in New Guinea. It is noteworthy that the genus Dendrochilum, so rich in species in Sumatra, Borneo and the Philippines, is represented in New Guinea by just one species, which is not even endemic.