Description from Flora of China
Bulbophyllum pectinatum var. transarisanense (Hayata) S. S. Ying; B. transarisanense Hayata; B. transarisanense f. alboviride Fukuyama; B. viridiflorum Hayata.
Rhizome 1.8-3 mm in diam., sections between pseudobulbs 0.4-1.2 cm, bract fibers hardly persistent. Pseudobulbs close together, ovoid to almost globose, not or hardly prostrate proximally, 1.1-2.5 × 0.6-1.5 cm. Petiole 0.3-1.5 cm; leaf blade elliptic to ovate, 3-8 × 0.9-2.3 cm, rounded to obtuse. Inflorescence erect to spreading, 6-10 cm, 1-flowered; peduncle 1.2-4.5 cm; bracts ca. 3, longest 6-9 mm; floral bracts tubular for 2/3 or more of their length, 6.5-14 mm, acute. Flowers resupinate, opening wide, pale greenish, often with fine reddish purple spots mainly along veins; lip pale green to white, stained or finely spotted with reddish purple. Pedicel and ovary 32-60 mm. Dorsal sepal recurved with top incurved, ovate, 13-23 × 5-13 mm, rather thin, glabrous, base rather narrowly attached, margin entire, apex obtuse to acute; lateral sepals free, recurved to spreading, elliptic to ovate-triangular, 15-26 × 11-14 mm, (sub-)acute, rather broadly attached, otherwise as dorsal sepal. Petals recurved to spreading, elliptic to ovate-triangular, 10-19 × 5-11 mm, rather thin, glabrous, base rather broadly attached, margins entire, apex obtuse to acute; lip recurved to almost reflexed at ca. 2/3 of its length, ovate-triangular, 10-16 × 7-18 mm (all without artificial spreading), thick but proximally thin toward margins; abaxially with a retuse median ridge up to ca. 2/3 of length of lip, surface glabrous; adaxially deeply concave proximally, with 2 retrorse, dorsiventrally flattened, rounded lobes close together and covering ligament, toward top slightly concave grading to distinctly convex and with 2 well-spaced, high, narrow, papillose ridges with a deeply erose crest, adaxially papillose-verrucose distally and sometimes in between ridges, surface otherwise glabrous, margins erose-lacerate, more deeply so proximally, apex obtuse. Column 2.5-5 mm, stigma inside with 3 keels, at its base without teeth, column foot without a tooth above ligament; stelidia deltoid, 1-2 mm, obtuse; anther abaxially ± glabrous and with a rounded crest; front margin drawn out, erose; pollinia with a fleshy stipe firmly attached to their bases. Fl. (Mar-)Apr-Jul(-Sep).
Epiphytic in forests, also found as a lithophyte along ravines; 1000-2700 m. Taiwan, SE to W Yunnan [NE India, Myanmar, N Thailand, Vietnam].