Bulbophyllum nocturnum J.J.Verm., de Vogel, Schuit. & A.Vogel, Bot. J. Linn. Soc. 167 (2011) 344–350, fig. 1-3.
Type: Leiden cult. 20080300 (holo LAE; iso L), from PNG, New Britain
Epiphytes. Roots sprouting near the base of the rhizome, growing backwards along it until reaching the substrate. Rhizome patent to pendulous, up to 15 by 0.3-0.4 cm; sections between pseudobulbs 2.4-3 cm long, scale leaves persistent. Pseudobulbs distant, ellipsoid-cylindrical, 1-1.5 by 0.4-0.5 cm. Leaves subsessile, elliptic to ovate; blade 5.3-6.2 by 2.1-3.2 cm, index (length/width) 1.8-2.5; abaxial surface corrugated; apex acute. Inflorescence c. 2 cm long, 1-flowered; peduncle porrect, c. 0.5 cm long; scale leaves 2, the longest c. 0.4 cm long; floral bract tubular, c. 0.6 cm long, with acute apex. Flowers opening widely. Pedicel with ovary c. 1 cm long; basal node on a c. 4 mm long stump. Median sepal spreading, ovate, thick, c. 1.4 by 0.4 cm, index c. 3.5; base broadly attached; surface glabrous; margins entire; apex acute. Lateral sepals free, triangular, otherwise as the dorsal sepal, c. 1.5 by 0.4 cm, index 3.7-3.8. Petals porrect, a narrow seam along the base of the column, entire, c. 0.1 by 0.2 cm, index c. 0.5; surface glabrous; with two types of stalked, papillose appendages along the top margin; the first type thick, widest near the base and gradually tapering to the top, 0.55-0.8 by 0.02-0.03 cm, at the base abruptly narrowed into a thread-thin, smooth stalk c. 0.2 cm long, at the apex acute; the second type much thinner, stalk-like, subulate, 0.3-0.35 cm long, gradually passing into a 0.15-0.2 cm long stalk; these appendages divided in three groups, 3 and 4 of the first type at the upper and lower edge of the petal, 3 of the second type in between. Lip , thick, c. 0.33 by 0.13 cm, index 2.5-2.6; with patent, triangular, acute lobes on the proximal 1/4-1/5 of the length of the lip; midlobe obovate; apex acuminate; upper surface constricted to a narrow, deeply furrowed, irregularly verrucate strip with irregular edges; lower surface inflated, somewhat furrowed, increasingly papillose with elongated papillae towards the tip. Column c. 0.24 cm long; stigma obovate, without keels inside; column foot slightly widened distally; stelidia c. 0.07 cm long, triangular, obtuse, upper margin erose, lower with a patent, deltoid, subacute tooth with a much smaller tooth on its front margin; anther-cap abaxially with a narrow crest, surface glabrous, front margin drawn out into a retuse beak; pollinia 4, inner ones c. half as long as the outer ones. (After Vermeulen et al., Bot. J. Linn. Soc. 167 (2011) 344–350, fig. 1-3.