Bulbophyllum section Pelma (Finet) Schltr., Repert. Spec. Nov. Regni Veg. Beih. 1 (1912) 703
Small to medium sized epiphytes. Rhizomes erect to approx. stiffly pendulous; rhizome bracts thin to thick, surface minutely colliculate to densely papillose or transversely rugate, rather persistent and finally often breaking up into transverse segments, veins rather persistent. Roots sprouting mainly near to the base of the rhizomes, growing backwards towards the substratum over or alongside the rhizome, glabrous or slightly and minutely hirsute locally. Pseudobulbs conspicuous compared to the size of the plant, 1-leafed, with shoots sprouting at or slightly above its (sub-)basal node and free, not fused to the pseudobulb. Leaves persistent, thick, veins inconspicuous. Inflorescences sprouting from or slightly above nodes along the length of the rhizome, single to few-fasciculate, 1-flowered or racemose with flowers distichous. Peduncle much shorter than the pseudobulbs, peduncle bracts 2— 6, scattered but most in the basal half of the peduncle. Rachis, if present, not thickened. Flowers per inflorescence several to all open at a time; floral bracts tubular; pedicel with the basal node well above the attachment of the floral bract, shorter than the ovary. Sepals free, the laterals 0.9— 1.5 times as long as the median; 1— 31 mm long, elliptic to triangular, rounded to caudate, margins entire, glabrous (ciliate or with glandular hairs in Bulbophyllum ankylorhinon and Bulbophyllum fractiflexum respectively); thin to thick, top often thickened; 1— 7-veined, surface glabrous. Petals 0.25— 9 mm long, elliptic to (ob-)ovate, rhombiform or spathulate, rounded to acute, margins entire to slightly erose (distally), glabrous to finely papillose distally; thin, 1— 3-veined, surface glabrous to finely papillose distally (margins and adaxial surface with coarse, elongated papillae in Bulbophyllum ankylorhinon). Lip mobile on a thin ligament, without auricles near the ligament, undivided (3-lobed in Bulbophyllum mesodon), 0.4— 3.8 mm long, elliptic to (ob-)ovate, oblong (panduriform in Bulbophyllum latipes), margins glabrous to finely papillose (with coarse, elongated papillae in Bulbophyllum ankylorhinon), surface glabrous to papillose; adaxially usually with an inconspicuous to distinct cavity immediately above the ligament (basal cavity, absent in Bulbophyllum ankylorhinon, Bulbophyllum colliferum), with two converging ridges, knobs or teeth (basal teeth), together forming a transverse wall with a notch half-way, separating it from the rest of the lip, distally to this wall with or without two hardly to distinctly converging ridges in approx. flexural position (with an additional median ridge in Bulbophyllum latipes). Column with rostellum front slightly receding in between the stelidia tips to distinctly and beak-like projecting beyond them, stigma large, without keels inside, proximally usually protruding or with a tooth, column foot with the free part short or long; usually just short of the ligament with a distinct median tooth which fits into the basal cavity of the lip. Stelidia shorter than 1/2 of the length of the column, or vestigial, if present approx. semi-elliptic to triangular, sometimes erose but approx. without teeth along the margins. Anther abaxially with a low or high, rounded crest, front somewhat concave or not, front margin not drawn out. Pollinia 4, with the inner half as long as the outer or longer; sometimes with a single, small, easily lost stipes.
New Guinea: 25 taxa. Altogether 26 accepted taxa (51 names): Sumatra, Java, Borneo, Philippines, Sulawesi, New Guinea, West Pacific. Range extension determined by Bulbophyllum absconditum J.J. Sm..
Section Pelma shares with section Peltopus the often conspicuous but not omnipresent tooth or callus on the column foot, locking into a basal cavity in the lip. This immobilizes the lip, although the ligament itself is flexible. Section Peltopus differs in usually having a creeping rhizome; the few species with a patent rhizome have the pedicel distinctly longer than the ovary, as well as minute petals.
The following taxa in this program belong to this Section:
Bulbophyllum absconditum subsp. hastula
Bulbophyllum savaiense subsp. gorumense
Bulbophyllum savaiense subsp. subcubicum