20. Oberonia acaulis Griffith, Itin. Pl. Khasyah Mts. 76. 1848.
显脉鸢尾兰 xian mai yuan wei lan
Stem rather short or inconspicuous. Leaves subbasal, 3 or 4, distichous-equitant, laterally compressed, ensiform, subfalcate, 4.5-17 × 0.7-1 cm, slightly thickened, veins conspicuous, base articulate, apex long acuminate. Peduncle subterete, 21-23 cm, nearly wingless, with a few very small sterile bracts or sometimes with a greenish foliaceous bract; rachis 14-17.5 cm, ca. 5 mm in diam., densely many flowered; floral bracts lanceolate, 1.5-2 mm, margin irregularly sharply toothed, apex long acuminate. Flowers greenish to yellowish white; pedicel and ovary 1-2 mm. Dorsal sepal ovate-elliptic, 0.8-1 × 0.5-0.6 mm, apex obtuse; lateral sepals broadly ovate, 0.8-1 × 0.6-0.7 mm. Petals oblong, 0.8-1 × ca. 0.5 mm, apex rounded; lip suboblong-ovate in outline, ca. 2 mm, 3-lobed; lateral lobes nearly subovate, margin erose, irregularly incised, or entire; mid-lobe bilobed at apex; lobules parallel to each other, oblong, broadly oblong, or ovate-lanceolate, 0.5-0.7 × 0.3-0.4 mm, apex obtuse, subtruncate, or acuminate. Column very short. Capsule subellipsoid, ca. 3 × 2 mm; fruiting pedicel ca. 0.5 mm. 2n = 30.
Epiphytic on trees in forests or along forest margins; 1000-2400 m. SE Xizang, S and SE Yunnan [Bhutan, India, Myanmar, Nepal, Thailand, Vietnam].