Bulbophyllum section Phreatiopsis J.J.Verm. & P.O'Byrne [in press]
Small to medium sized epiphytes. Rhizomes creeping, sometimes straggling; rhizome bracts thin to rather thick and papyraceous, surface approx. glabrous, caducous including the veins. Roots sprouting along the rhizome, speading, approx. glabrous to finely hirsute. Pseudobulbs minute to rather small compared to the size of the plant, 1-leafed, with shoots sprouting from its basal node and free, not fused to the pseudobulb. Leaves persistent, thick, veins inconspicuous. Inflorescences sprouting from nodes along the rhizome or from the basal node of the pseudobulb, single, racemose with flowers spirally arranged. Peduncle somewhat overtopping the leaves or not, peduncle bracts 4— 11, scattered, the upper approx. half-way the length of the peduncle or above. Rachis not thickened. Flowers per inflorescence many or all open at a time; floral bracts not amplexicaul; pedicel with the basal node level with the attachment of the floral bract, as long as or distinctly longer than the ovary. Sepals free, 3— 5.5 mm long, the laterals not or hardly longer than the median; elliptic to ovate-triangular, rounded to subacute, margins entire, approx. glabrous or finely papillose distally; rather thin to rather thick; 3-veined, surface glabrous to finely papillose distally. Petals 1.9— 3.8 mm long, ovate to oblong, rounded to subacute, margins entire, glabrous to finely papillose distally; rather thin, 1-veined, surface adaxial surface glabrous to papillose distally. Lip mobile on a thin ligament, with antrorse, rounded auricles near the base or not, undivided, 2.3— 4 mm long, ovate(-oblong), margins entire, glabrous or finely papillose, surface glabrous or finely papillose; adaxially near he base concave and with a triangular callus, distally continuing as an inconspicuous to distinct median ridge, with two more, longer and converging ridges in approx. flexural position. Column with rostellum front receding in between the stelidia tips, stigma large, without keels inside, proximally not protruding, column foot with the free part short, with or without inconspicuous, small lateral teeth near the ligament. Stelidia (slightly) shorter than 1/2 of the length of the column, distinct, triangular, with or without a small tooth along the upper margin, with a patent, deltoid, broadly rounded to acute wing along the lower. Anther abaxially with an inconspicuous, rounded crest, front not concave, front margin not drawn out. Pollinia 4 with the inner approx. half as long as the outer, without appendages.
New Guinea: 1 taxon. Altogether 2 accepted taxa (3 names): Peninsular Malaysia, Borneo, Sulawesi, New Guinea.
Distribution. 2 species (3 names): Peninsular Malaysia, Borneo, Sulawesi, New Guinea.
One species, Bulbophyllum phreatiopse, provisionally included in section Hirtula in Vermeulen (2002: 110). The species is an odd element in that section, only partly and indistinctly showing the distinguishing set. The two species included here do not satisfactorily fit in any section, they are better kept apart with as distinguishing character the triangular callus on the adaxial side of the lip. Their phylogenetic affinity seems uncertain.
The following taxa in this program belong to this Section: