Genus Bulbophyllum section Altisceptrum
Bulbophyllum sect. Altisceptrum J.J.Sm., Bull. Jard. Bot. Buitenzorg, ser. 2, 13 (1914) 34. Type species: Bulbophyllum elongatum (Blume) Hassk.
Medium sized to large epiphytes. Roots sprouting mainly below the pseudobulbs, or also from rhizome nodes in between, spreading , approx. glabrous to rugose. Rhizomes creeping; rhizome scales thin to rather thick and papyraceous, approx. glabrous, caducous including the veins. Pseudobulbs rather conspicuous 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. Inflorescence a contracted to elongate raceme, sprouting from the basal node of the pseudobulb, single, racemose with flowers spirally arranged; peduncle longer than the pseudobulbs but not overtopping the leaves; peduncle scales scattered, the upper one just below the base of the rachis; rachis not thickened. Flowers many or all open simultaneously per inflorescence, resupinate, spirally arranged; pedicel usually with the basal node level with the attachment of the floral bract, distinctly longer than the ovary; floral bracts not amplexicaul. Sepals free, about equal, glabrous to erose-papillose or ciliolate, thin to rather thick, surface glabrous to partly and finely papillose-pubescent; the laterals not or hardly longer than the median, elliptic to triangular; margins entire; apex rounded to caudate, top thickened or not; 3-nerved. Petals triangular and widest at the base, or widest in the basal part and then narrowed and tapering towards the tip, thin to thick, glabrous to finely papillose or ciliolate, surface glabrous to partly and finely papillose-pubescent; margins entire to finely erose; apex obtuse to acuminate, with top thickened or not; 1-nerved (3-nerved in Bulbophyllum nemorale). Lip mobile on a thin ligament, undivided (sub-3-lobed in Bulbophyllum nemorale), (oblong-)ovate to triangular, glabrous to papillose to ciliolate; margins entire; upper surface without ridges, or with a median ridge and/or with two parallel or more or less converging ridges (with 2 more knobs near the base in Bulbophyllum nemorale), surface glabrous to finely papillose locally. Column with rostellum in front receding in between the stelidia tips; stigma small or large, without keels inside, near the bas not protruding; column foot with the free part short or virtually absent (in Bulbophyllum elongatum elongated so that a small or distinct gap exists between the petals and the lateral sepals), with inconspicuous, small lateral teeth near the apex; stelidia shorter than half the length of the column, distinct, triangular to subulate, with or without a small tooth along the upper and/or the lower margin; anther with a (low) rounded crest, in front somewhat concave or not, front margin not drawn out; Pollinia 4 with the inner ones less than half as long as the outer ones or longer; without appendages.
(after Vermeulen in Pridgeon & al. (eds.) 20xx).