Bulbophyllum section Peltopus Schltr., Repert. Spec. Nov. Regni Veg. Beih. 1 (1912) 700
Minute to rather small epiphytes. Rhizomes creeping or straggling, sometimes shortly ascending to patent (stiffly long-pendulous in Bulbophyllum subapetalum); rhizome bracts thin to thick, approx. glabrous to minutely colliculate, caducous including the veins. Roots sprouting mainly below the pseudobulbs (growing over or alongside the rhizome towards the substrate in species with ascending or patent rhizome), glabrous or slightly and minutely hirsute locally. Pseudobulbs conspicuous compared to the size of the plant, 1-leafed, with shoots sprouting at its basal node and free, not fused to the pseudobulb (sprouting from the distal half of the pseudobulb, well above its basal node, in Bulbophyllum subapetalum). Leaves persistent, thick, veins inconspicuous. Inflorescences sprouting slightly above nodes along the length of the rhizome (observed in species with an elongated rhizome only), single to fasciculate, 1-flowered. Peduncle usually longer than the pseudobulbs (shorter in e.g. Bulbophyllum brassii), peduncle bracts 2— 5, scattered but most in the basal half of the peduncle. Flowers per sympodium branch 1 open at a time; floral bracts tubular; pedicel with the basal node well above the attachment of the floral bract, distinctly longer than the ovary. Sepals free, the laterals not or hardly longer than the median; 3.6— 130 mm long, elliptic, (ob-)ovate to triangular, subacute to caudate, margins entire, sometimes slightly erose, glabrous to papillose or ciliate; thin, 3(— 5)-veined, surface glabrous or finely papillose to hirsute adaxially. Petals vestigial or minute compared to the size of the flower (more conspicuous in e.g. Bulbophyllum discolor), up to 5 mm long, if present, elliptic to (ob-)ovate, deltoid to (inverted) triangular, rounded to acuminate, margins entire to erose, glabrous to ciliate; thin, 1-veined (3-veined in Bulbophyllum concavibasalis), surface glabrous. Lip mobile on a thin ligament, without auricles near the ligament, undivided, 0.7— 21 mm long, orbicular, elliptic, oblong, (ob-)ovate to triangular, (approx. crescent-shaped in Bulbophyllum origami), margins entire to erose, glabrous to papillose, ciliate or with elongated papillae; adaxially usually with an inconspicuous to distinct cavity immediately above the ligament (basal cavity, absent in Bulbophyllum cycloglossum, Bulbophyllumkenae), 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 often with a second cavity, sometimes bordered by two parallel to distinctly converging ridges in approx. flexural position (sometimes proximally fused to a distinct median ridge), adaxial surface glabrous to papillose or pubescent (with coarse elongated papillae in Bulbophyllum ortalis); abaxial surface glabrous to papillose (partly ciliate in Bulbophyllum kenae). Column with rostellum front drawn out into a distinct, beak-like projection, stigma large, without keels inside, proximally protruding or not, column foot with the free part short to very long; usually just short of the ligament with a (distinct) median tooth which fits into the basal cavity of the lip. Stelidia vestigial. Anther abaxially with a low or high, rounded crest, front not or slightly concave, front margin usually not drawn out. Pollinia 4, with the half as long as the outer or longer; with a single small stipes (easily lost).
New Guinea: 32 taxa. Altogether 33 accepted taxa (43 names): New Guinea, West Pacific.
The joint between the lip and the column foot is similar to that in section Pelma. Bulbophyllum subapetalum J.J. Sm., has flowers characteristic for the section but is aberrant in having a pendulous rhizome and the young shoots sprouting near the top of the pseudobulb.
The following taxa in this program belong to this Section:
Bulbophyllum discolor subsp. cubitale