Iridorkis caulescens (Lindley) Kuntze; Malaxis caulescens (Lindley) H. G. Reichenbach; Oberonia auriculata King & Pantling; O. bilobatolabella Hayata; O. longilabris King & Pantling; O. pterorachis C. L. Tso; O. yunnanensis Rolfe.

Stem 1-4.5 cm. Leaves 5 or 6, distichous, laterally compressed, linear, often ± falcate, 1.5-5 × 0.2-0.4 cm, thick, veins obscure, base articulate, margin often crisped when dried, apex acuminate or acute. Peduncle subterete, (3-)5-11 cm, wingless; sterile bracts several, lanceolate, 2-2.5 mm; rachis (2.5-)4-10 cm, 5-6 mm in diam., many flowered; floral bracts lanceolate, 1.5-2(-3) mm, margin irregularly incised or nearly entire, apex acuminate or obtuse. Flowers pale yellow or pale green; pedicel and ovary ca. 2 mm. Dorsal sepal ovate-elliptic, 0.8-1 × ca. 0.6 mm, apex obtuse; lateral sepals subovate, slightly concave, similar to dorsal sepal in size. Petals suboblong, 0.8-1 × ca. 0.3 mm, apex subrounded or ± truncate; lip obovate-oblong or obovate in outline, 1.6-2 × ca. 1.3 mm, deeply bilobed, base with obtuse or inconspicuous auricles; lobules narrowly ovate, ovate, or sublanceolate, 0.7-0.9 mm, apex shortly acuminate or acute. Column short, stout. Capsule obovoid-ellipsoid, 2-2.3 × ca. 1.3 mm; fruiting pedicel ca. 1 mm. Fl. and fr. Jul-Oct. 2n = 26, 30.

Epiphytic on trees or lithophytic on rocks in forests; 700-2600(-3700) m. Guangdong, W Hubei, S Hunan, W Sichuan, Taiwan, SE Xizang, W to SE Yunnan [Bhutan, India, Nepal, Vietnam].