Bulbophyllum chalcochloron J.J.Verm., Nordic J. Bot. 26 (2008) 154, fig. 15
Type: Jongejan cult. 1567 (holo L), from PNG
Roots sprouting mainly below the pseudobulbs. Rhizome 1-1.2 mm in diameter, sections between pseudobulbs 0.2-0.4 cm long, creeping or shortly ascending, bracts not persistent. Pseudobulbs 0.3-0.8 by 0.3-0.4 cm, borne close together, (sub-) erect, ellipsoid to (ob-)ovoid. Leaves: petiole 0.4-0.6 cm long; blade 1.8-3 by 0.2-0.32 cm, index (length/width) 6.7-12.5, elliptic, acute or apiculate. Inflorescence 11-12.5 cm long, 1-flowered; peduncle 10-11.3 cm long, erect to patent; non-floriferous bracts c. 2, the longest c. 2.5 mm long; floral bract c. 1.6 mm long, tubular, acute. Flowers moderately opening. Pedicel-with-ovary c. 1.9 mm long, basal node coinciding with the bract attachment. Dorsal sepal c. 6 by 1.5 mm, index c. 4, recurved, ovate, acute, margins finely and densely ciliate, base broadly attached, thin, surface glabrous. Lateral sepals c. 6 by 1.2 mm, index c. 5, fused along their lower margins, margins entire, otherwise as the dorsal sepal. Petals c. 6 by 1.2 mm, index c. 5, porrect, elliptic excluding the top part, including the caudate top 2.7 mm long, margins finely and densely ciliate, the cauda ciliolate, base narrowly attached, thin, surface glabrous but cauda finely shortly-hairy. Lip c. 1.8 by 1 mm, index c. 1.8, recurved about half-way, general outline obovate with a small but distinct constriction about half-way, rounded, margins with one pair of retrorse, ovate, obtuse auricles close to the ligament, beyond these the lip margins erect and entire, but half-way the lip abruptly folded backwards and with long-baculiform papillae, rather thin, surface glabrous; adaxially concave proximally, with a transverse median callus just above the base, convex distally with two distinct folds near the top, on either side of the median line, creating a distinct, broadly rounded apical callus; abaxially without a median ridge, convex proximally, concave and with a deep median furrow distally. Column c. 1.2 mm long; stigma subrectangular, without keels inside; foot not or hardly widened; stelidia c. 0.8 mm long, narrowly triangular, subacute, with a slight, obtuse edge along the upper margin; anther-cap abaxially with a large, dorsiventrally flattened crest overtopping the front margin, surface papillose, front margin drawn out into a broadly rounded, thin beak; pollinia 4, obovoid, the inner about half as long as the outer, distinctly flattened; no appendages. (After Vermeulen, 2008)
Colours: Flower green with reddish purple nerves, margins, and petal tips, column white.
Distribution: Malesia (New Guinea).
Distribution in New Guinea: Papua New Guinea.