Bulbophyllum callichroma Schltr., Repert. Spec. Nov. Regni Veg. Beih. 1 (1913) 886
Type: Schlechter 18136 (holo B, lost; iso AMES, K, L)
Rhizome creeping, 0.15-0.3 cm; all rhizome scales slightly shorter to longer than the internodes. Roots in tufts below each pseudobulb. Pseudobulbs ovoid, 2-7 cm apart, 0.7-1.5 by 0.6-1.5 cm, not laterally flattened. Petiole 6-20 mm. Leaf blade ovate to elliptic, 4.5-16 by 1.4-2.3 cm, index 3-8.7; tip acute to acuminate. Inflorescence 18-43 cm, 95 4-14-flowered; peduncle 12.5-30 cm. Floral bracts 5-8. the longest 4-7 mm. Rachis approximately pendulous, 4.5-13 cm. Floral bracts triangular, 2-4 mm; tip acute. Pedicel and ovary 6-8.5 mm, with the node 0.08-0.25 cm from the floral bract. Flowers many open time, moderately opening. Median sepal with two folds along the midrib near the base, ovate, 9-19 by 3-8 mm, index 1.9-3.5; tip acute to acuminate; rather thin, often thickened towards the tip, glabrous. Lateral sepals usually connate (see note), oblique, ovate to elliptic, 10-24 by 3.3-7.5 mm, index 3.2-5; tip acute to acuminate; rather thin, glabrous. Petals ovate to elliptic, 3.2-7 by 2-4 mm, index 1.4-1.9; tip obtuse to acute, thin, glabrous. Lip curved, general outline ovate to sub-panduriform, 2-3 by 1-1.8 mm, index 1.4-2 (not spread); tip rounded, thick, glabrous; adaxially concave near the base, with 2 distinct ridges converging and fused in front approximately half-way, abaxially with a retuse median ridge. Column from ovary to the tip of the stelidia 1.3-2 mm; stigma with a distinct tooth at its base, approximately sickle-shaped. Column-foot approximately without accessories. Stelidia (obliquely) truncate. Anther abaxially with a ridge towards its base; front margin protruding. Pollinia 4; the inner pair less than half as long as the outer pair. (After Vermeulen, 1993)
Colours: Median sepal white with a yellow tip, or entirely yellow, with or without purple stains or veins. Lateral sepals purple, sometimes with whitish margins. Petals white. Lip purple.
Habitat: Epiphyte in lower montane forest; 600-1700 m.
Flowering time in the wild: April, June, July, August, September.
Distribution: Malesia (New Guinea).
Distribution in New Guinea: Papua (Indonesia); Papua New Guinea; see map 96-268M.jpg.
Cultivation: Intermediate growing epiphyte.