Bulbophyllum section Sestochilos (Breda) Benth. & Hook.f., Gen. Pl. (1883) 502
(Small to) medium-sized epiphytes. Rhizomes creeping, sometimes straggling; rhizome bracts thin to rather thick, surface approx. glabrous, caducous but veins persistent as whorls of thick, stiff fibres around the rhizome. Roots sprouting from nodes along the length of the rhizome, spreading, glabrous. Pseudobulbs (rather) inconspicuous compared to the size of the plant, 1-leafed, with shoots usually sprouting from its basal node and free, not fused to the pseudobulb. Leaves persistent, thick, veins inconspicuous. Inflorescences sprouting from nodes along the length of the rhizome, single, 1-flowered. Peduncle (distinctly) shorter than the pseudobulbs, peduncle bracts 2— 6, (sub-)basal, the upper slightly below half-way the peduncle. Flowers: pedicel with the basal node well above the attachment of the floral bract, distinctly longer than the ovary; floral bracts amplexicaul, not tubular or tubular near the base only. Sepals free, the laterals approx. as long as the median or somewhat shorter; 12— 55 mm long, elliptic, (ob-)ovate to triangular, obtuse to acuminate, glabrous, rather thick, 7— 13-veined. Petals 11— 46 mm, elliptic to ovate-triangular, obtuse to acuminate, glabrous, rather thick, 5— 8-veined. Lip mobile on a thin ligament, without auricles near the ligament, undivided, 3.5— 35 mm long, often with a wide, triangular, hastate to cordate basal part and a narrow, drawn out top part, also elliptic to (ob-)ovate, glabrous; adaxially often more or less concave near the base, without ridges, or with two parallel or more or less converging ridges in flexural position. Column with rostellum front approx. level with the stelidia tips, stigma large, with 3 keels inside (two distinct but sometimes short on the front wall, a single long, but sometimes less distinct median on the back wall), proximally not protruding, column foot tapering towards the tip or not, with the free part short to very long; without teeth. Stelidia less than half the length of the column, deltoid to triangular, without a tooth along the upper margin, with or without a tooth along the lower. Anther abaxially with a rather low rounded crest, front not concave, front margin not drawn out. Pollinia 4, of approx. equal length; without appendages.
New Guinea: 16 taxa, 1 more introduced. Altogether 23 accepted taxa (36 names): from Myanmar, Thailand, Indochina to Java, east to West Pacific.
A revision is in preparation (Vermeulen). Unusually uniform in vegetative and floral morphology; distinguishing characters mainly found in the lip and the column.
The following taxa in this program belong to this Section: