Description from Flora of China
Iridorkis pachyrachis (H. G. Reichenbach ex J. D. Hooker) Kuntze; Oberonia umbraticola Rolfe.
Stem ca. 1 cm. Leaves subbasal, several, inconspicuously distichous-equitant, laterally compressed, ensiform, sometimes slightly falcate, 7-10 × 0.6-1.5 cm, thick, veins obscure, base articulate, apex acute or acuminate. Peduncle foliaceous and fused with leaf in basal half, appearing to arise from inner side of leaf blade; rachis thickly fleshy, many flowered; racemes spikelike; floral bracts ovate-orbicular, ca. 0.8 mm, margin irregularly incised. Flowers pale brown, very small; pedicel and ovary very short, conspicuously shorter than floral bracts. Sepals ovate or elliptic, ca. 0.8 × 0.5 mm, apex obtuse. Petals narrowly oblong, ca. 0.7 × 0.2 mm, apex obtuse; lip ovate, slightly longer than sepals, margin entire, with obtuse basal auricles, apex obtuse or acute. Column short, stout. Capsule subovoid-ellipsoid, ca. 2 × 1.3 mm, with a very short pedicel. Fl. Nov-Mar, fr. May. 2n = 30.
Epiphytic on trees in dense forests; ca. 2100 m. S Xizang, SW Yunnan [Bhutan, N India, Myanmar, Nepal, Thailand, Vietnam].