Bulbophyllum section Stachysanthes (Blume) Aver., Ident. Guide Vietnamese Orchids (1994) 276
Minute to large epiphytes. Rhizomes creeping, or erect to pendulous; rhizome bracts thin, glabrous to colliculate, caducous including the veins, or veins slightly to distinctly persistent as fibres. Roots sprouting along the rhizome or mainly below the pseudobulbs, spreading; in species with a patent to pendulous rhizome below the older pseudobulbs only, growing over or alongside the rhizome towards the substrate; glabrous to finely hirsute locally. Pseudobulbs minute compared to the size of the plant, 1-leafed, with shoots usually sprouting from (in some species well above) the node below its basal node and free, not fused to the pseudobulb. Leaves persistent, thick, veins inconspicuous. Inflorescences usually sprouting from or somewhat below the basal node of the pseudobulb, single or sometimes 2 together and racemose with flowers spirally arranged, or sometimes fasciculate and 1-flowered. Peduncle usually as long as the leaves or shorter, peduncle bracts 3— 9, scattered, or with the upper at or below half-way the peduncle. Rachis, if present, usually not thickened. Flowers per inflorescence few to many open at a time; floral bracts not amplexicaul (amplexicaul in some species with 1- or few-flowered inflorescences); pedicel with the basal node level with the floral bract attachment, distinctly shorter to longer than the ovary. Sepals free, sometimes all three adherent to connate with a lumen between the laterals, the laterals approx. 1— 1.5 times as long as the median; 2— 40 mm long, elliptic, (ob-)ovate to triangular, rounded to caudate, glabrous, thin to thick, top thickened or not; 3-veined. Petals 1— 7 mm long, elliptic to (ob-)ovate, obtuse to acuminate, margins entire to distally slightly erose, glabrous to papillose; thin, 1-veined, adaxial surface glabrous to minutely papillose distally. Lip mobile on a thin ligament, without auricles near the ligament, undivided, 1— 9 mm long, elliptic to (ob-)ovate to oblong, margins entire to slightly erose, glabrous to papillose to ciliate; adaxially without ridges, or often with two (distinctly converging) flexural ridges, and/or with two short converging ridges, knobs or teeth close to the base, or with two parallel ridges slightly further above the base, surface glabrous to papillose distally; abaxial surface approx. glabrous. Column with rostellum front receding in between the stelidia, stigma large, without keels inside, proximally protruding or not, or with a distinct tooth, column foot tapering towards its top, free part (rather) short to virtually absent; with or without a small median callus just short of the ligament, or auricles near the ligament. Stelidia shorter to longer than 1/2 of the length of the column; usually short but not vestigial, approx. deltoid to triangular, upper margin without teeth, lower margin often with a deltoid to triangular, rounded to acute wing or tooth. Anther abaxially with a (low) rounded crest, front concave or not, front margin drawn out into a beak or not. Pollinia 2; without appendages or with a single stipes.
Distribution
New Guinea: 1 taxon; Bulbophyllum unguiculatum probably also occurs in New Guinea, but no data. Altogether 67 provisionally accepted taxa (166 names): India, China, Taiwan, Eastwards to West Pacific. Speciose in Peninsular Malaysia to The Philippines and Sulawesi, elsewhere represented by few species only.
Notes
Generally characterized by the minute pseudobulbs, combined with an absence of other outstanding features, and flowers lacking purple colouring.
The following taxa in this program belong to this Section:
Bulbophyllum apodum