Bulbophyllum section Monosepalum (Schltr.) J.J.Sm., Nova Guinea 12 (1916) 374
Medium-sized epiphytes or terrestrials. Rhizomes creeping or straggling; rhizome bracts 5— 7 per shoot, thin, surface approx. glabrous, rather persistent. Roots sprouting mainly below the pseudobulbs, spreading, glabrous. Pseudobulbs (in-)conspicuous compared to the size of the plant, 1-leafed, with the shoots sprouting from, or slightly above their basal node, or from the sub-basal node, and free, not fused to the pseudobulb. Leaves persistent, thick, veins inconspicuous to distinct. Inflorescences sprouting from nodes along the length of the rhizome; single, 1-flowered. Peduncle longer than the leaves, bracts 2— 4, scattered with the upper well above half-way the peduncle. Flowers pendulous; floral bracts tubular; pedicel with the basal node well above the attachment of the floral bract, longer than the ovary. Sepals: the median adherent to the laterals for most of their length, all of equal length, 46— 85 mm long, elliptic to ovate-triangular, acute, margins entire, glabrous; rather thin, 5-veined, adaxial surface glabrous to papillose-verruculate, abaxial surface glabrous to coarsely verruculate proximally. Petals 2— 5 mm long excluding appendages, (transversely) elliptic to dolabriform, truncate to broadly rounded and with 3 appendages, margins entire or lobed, glabrous; thin, 3-veined, surface glabrous or adaxially with a papillose patch in the centre; appendages differing in texture from the petal itself, not of equal shape, papillose. Lip mobile on a thin ligament, without auricles, undivided, 3.5— 4.5 mm long, ovate to oblong, margins entire, papillose(-ciliate), surface partly papillose or hirsute; adaxially concave near the base, with 2 approx. parallel, distinct, rounded ridges running almost over the entire length of the lip. Column with rostellum front receding in between the stelidia, stigma narrow, slit-like, without keels inside, proximally protruding or not, column foot more or less widening and thickening towards the tip; free part long, with a median tooth just short of the ligament. Stelidia slightly shorter than of the column length, distinct, narrowly triangular to subulate, with or without a somewhat erose upper margin, without tooth along the lower. Anther abaxially with a rounded crest, front turned backwards, inflated and concave, front margin distinctly drawn out. Pollinia 4, with the inner almost as long as the outer, without appendages
New Guinea: 3 taxa (3 names). Endemic.
Uniquely identified by the appendages on the petals, combined with the adherent sepals. The pollinia pairs seem very firmly fused together (in sicco).
The following taxa in this program belong to this Section: