Bulbophyllum macrobulbum J.J.Sm., Bull. Dép. Agric. Indes Néerl. 39 (1910) 4
Type: Bogor cult. (Exp. Lorentz Exp., Rachmat 63) s.n.; (83) s.n.; (109) s.n. (later duplicate L); s.n. probable isosyntypes L)
Pseudobulbs closely spaced, large, thick, ovoid, in cross-section broadly-subelliptic, obtusely angular, becoming rugose, 5.5-8 cm long, 4-6 cm diam., 1-leaved. Leaf lanceolate, towards the apex somewhat dilated, at the apex very shortly acute and recurved, base narrowed conduplicate and semitwisted, mid-rib grooved above, underneath obtusely keeled, margins recurved, carnose, c. 21 by 6.5 cm. Inflorescences from the rhizome close to the base of the pseudobulbs, several, clustered, short, c. 2-4-flowered; peduncle very short, 0.7 cm long, entirely covered with ovate, at the base tubular, acuminate, concave, somewhat fleshy peduncle-scales that become larger upwards, passing into the floral bracts; rachis very short. Floral bracts broadly ovate, acutely acuminate, concave, c. 13-nerved, membranous, 1.5-1.6 by 1.2 cm. Flowers large, carnose, fetid, 2.9 cm wide, 5.75 cm long. Median sepal obliquely erect, ovate, channelled-subulate-acuminate, concave, 4 cm long, 2.1 cm wide. Lateral sepals inserted on the column-foot remote from the median sepal, 2.4 cm long, when flattened 1.65 cm wide; along the lower margins except for the apex convex, along the upper margins, the apex excepted, cohering into a keel; decurved, falcate-oblong, apex long channelled-subulate-acuminate, concave, dorsally obtusely indistinctly keeled; mentum short, broadly rounded. Petals parallel, at the apex recurved, in outline obliquely rhombic, in total 2.7 by 1.6 cm, claw broad, at the base oblique, convex, thick-fleshy; blade thinner textured, ovate-triangular, apex filiform subulate-acuminate, with crispate margins, sparsely pilose. Lip strongly mobile, carnose, oblong-cordate, 1.2 cm long, at the base 0.63 cm wide, obtuse, curved, with two vertical basal lobes, adaxially with two keels which are parallel in the upper part and in the basal part are decurrent on the lobes and border a deep basal concavity, this concavity is at the base delimited by a transverse notched lamella, and is divide into three locules by a transverse and a longitudinal rib, the whole lip warty-rugose, below with a deep groove delimited by two keels. Column thick, hard, 0.75 cm long; clinandrium small, deep, the subulate filament shorter than the stelidia; stelidia porrect, much surpassing the anther, subulate, laterally compressed, sharply acute, margins below the stelidia produced into short rounded wings; column-foot making an acute angle with the ovary, strongly incurved, at the base very broad, towards the apex strongly narrowed, truncate, in upper half free, when flattened 1.6 cm long, at the base 1.1 cm wide. Anther cucullate, 0.27 cm long. Pollinia 4, obliquely elliptic, laterally compressed, 0.25 cm long. Stigma small, longitudinal, oblong, deeply concave. Pedicel strongly curved; ovary obconical, 6-grooved, 0.7 cm long. (After Smith, 1911)
Colours: Pseudobulbs dull olive green. Leaves glaucous-green, margins and mid-rib purple, especially underneath pruinose. Floral bracts dull whitish, slightly suffused with purple and green. Median sepal yellowish white, minutely spotted dark purple, the spots in the basal part merging. Lateral sepals similar in colour, but the spots more merging. Petals yellowish white, with dark purple warts and spots; claw dark purple. Lip at the base yellow, near the apex dull purple. Column yellowish white. Anther pale ochrish yellow, dotted with dark purple. Pollinia yellow. Ovary greenish white.
Habitat: Epiphyte; 300-1000 m.
Flowering time in the wild: June, July, October, November, December.
Distribution: Malesia (New Guinea).
Distribution in New Guinea: Papua (Indonesia); Papua New Guinea; see map 96-1077M.jpg.
Cultivation: Warm growing epiphyte, requires light position.