Bulbophyllum argoxanthum J.J.Verm., Nordic J. Bot. 26 (2008) 164, fig. 20
Type: Leiden cult. 20030126 (holo L), from PNG, Woitape
Roots sprouting near the base of the rhizome, growing backwards along it until reaching the substrate. Rhizome 4.5-5 mm in diameter, sections between pseudobulbs 3-4.5 cm long, patent to pendulous, bracts persistent. Pseudobulbs 2.8-3.2 by 0.6-0.8 cm distant, ellipsoid. Leaves: petiole c. 0.3 cm long; blade ovate, 9.4-10.2 by 3.1-3.4 cm, index (length/width) 2.7-3.3, acute. Inflorescence 1.8-3 cm, porrect, a distichous, dense 6-9-flowered raceme; peduncle 1-1.2 cm; non-floriferous bracts c. 3, the longest c. 4.5 mm long; rachis 1.6-2 cm long; floral bracts c. 3.5 mm long, acuminate. Flowers non-resupinate, not fully opening, many simultaneously. Pedicel-with-ovary c. 2-3 mm long, basal node on a 5-7 mm long stump. Dorsal sepal c. 4 by 2.7 mm, index c. 1.5recurved, ovate-elliptic, rounded, margins entire, base rather broadly attached, thin, glabrous. Lateral sepals 3.8 by 2.2 mm, index c. 1.7, free, oblique, ovate, otherwise as the dorsal sepal. Petals c. 2.6 by 1.6 mm, index c. 1.6, recurved, obovate, rounded, margins entire, base rather narrowly attached, thin, glabrous. Lip c. 2 by 1.5 mm, index c. 1.3 (not flattened), recurved about half-way, elliptic, rounded, thick, surface glabrous; adaxially with a deep basal cavity, in front delimited by two converging teeth which together form a transverse ridge with a slit half-way, with two more inconspicuous, obtuse ridges starting near the base, at the margins, and converging up to half-way along the lip, area in between concave, elsewhere convex; abaxially with a wide, truncate median ridge proximally, elsewhere slightly concave. Column c. 0.8 mm long; stigma elliptic, inside without keels, proximally protruding; foot with a distinct, conical, obtuse median tooth just above the ligament; stelidia c. 0.3 mm long, deltoid, acute; anther-cap abaxially colliculate, with a widely rounded crest overtopping the front margin, front margin not drawn out, entire; pollinia 4, ellipsoid, the inner about as long as the outer, much flattened; no appendages. (After Vermeulen, 2008)
Colours: Sepals and petals greenish yellow, lip pale orange, underside creamy-yellow at the base, column and anther-cap cream-coloured, unscented.
Flowering time in the wild: December.
Distribution: Malesia (New Guinea).
Distribution in New Guinea: Papua New Guinea; Papua New Guinea; see map 96-2267M.jpg.