Bulbophyllum zygochilum J.J.Verm., Nordic J. Bot. 26 (2008) 177, fig. 25
Type: Leiden cult. 950220 (holo L), from Indonesia, Papua, Bird's head Peninsula
Roots sprouting mainly below the pseudobulbs. Rhizome 1.5-2 mm in diameter, sections between pseudobulbs 0.5-1.5 cm long, creeping or somewhat straggling at some distance from the substrate, bracts not persistent. Pseudobulbs 1-2.3 by 0.5-0.7 cm, distant to rather close together, (obliquely) erect, ovoid. Leaves: petiole 0.2-0.5 cm long; blade 3-4.7 by 0.85-1.1 cm, index (length/width) 3.5-4.3, ovate, acute-apiculate. Inflorescence 20-22 cm long, 1-flowered; peduncle 16-18 cm long, erect to patent; non-floriferous bracts c. 4, the longest c. 2 mm long; floral bract c. 2.8 mm long, tubular, acute. Flowers fully opening. Pedicel-with-ovary c. 9 mm long, basal node on a c. 2 mm long stump. Dorsal sepal c. 27 by 4 mm, index 6.7-6.8, reflexed, ovate, caudate, margins finely erose, thinly but densely ciliate, base narrowly attached, rather thin, adaxial surface glabrous, abaxial surface sparsely papillose to shortly-hairy. Lateral sepals c. 40 by 5.5 mm, index c. 7.2, free, recurved to spreading, obliquely ovate, caudate with gradually thickened tips, upper margin shortly but rather densely ciliate, lower margin densely ciliate, adaxial surface with a narrow strip of densely placed, minute, irregularly shaped verrucae close to the lower margin, otherwise as the dorsal sepal. Petals c. 6 by 2.5 mm, index c. 2.4, porrect, triangular, acuminate, margins papillose-ciliolate proximally, ciliate distally, base narrowly attached, rather thin, surface shortly-hairly distally. Lip c. 1.3 by 1 mm, index c. 1.3 (not flattened), recurved, oblong, rounded, margins entire, with long, straight, thick hairs except near the base, thick; adaxially concave near the base, with two distinct ridges starting near the base, close to the margins, and running up, while slightly converging and then diverging, to close to the tip of the lip, adaxial surface partly finely papillose and with longer papillae and hairs near the margins; abaxially with a deeply retuse median ridge up to half of the length of the lip, surface papillose but with two patches of longer hairs about half-way along the length of the lip. Column c. 1.5 mm long; stigma elliptic, without keels inside, with a slight swelling well below its base; foot widened, with distinct, rounded lateral teeth just above the ligament; stelidia c. 0.7 mm long, triangular, acute, with a slight widening along the lower margin; anther-cap abaxially with a large, rounded crest over almost its entire length, surface finely papillose, front margin drawn out, widely rounded, papillose; pollinia 4, obovoid, the inner as long as the outer, flat; no appendages. (After Vermeulen, 2008)
Colours: Sepals wine-red, the dorsal yellowish towards the margins, the laterals with a yellowish row of verrucae close to the lower margin, petals wine-red with blackish hairs, lip wine-red.
Distribution: Malesia (New Guinea).
Distribution in New Guinea: Papua (Indonesia); see map 96-2344M.jpg.