Description from Flora of China
Corallorhiza patens Lindley, Gen. Sp. Orchid. Pl. 535. 1840; Diplolabellum confluens (Handel-Mazzetti) Garay & W. Kittredge; Oreorchis gracilis Franchet & Savatier; O. gracilis var. gracillima Hayata; O. gracillima (Hayata) Schlechter; O. lancifolia A. Gray; O. patens var. confluens Handel-Mazzetti; O. patens var. gracilis (Franchet & Savatier) Makino ex Schlechter; O. patens var. gracillima (Hayata) S. S. Ying; O. setschuanica Ames & Schlechter; O. wilsonii Rolfe ex Adamson; O. yunnanensis Schlechter.
Plants 25-70 cm tall. Pseudobulb ovoid to subellipsoid, 1-2 × 0.5-1.5 cm, 2- or 3-noded, sometimes persisting and forming a chain of pseudobulbs connected by a short rhizome. Leaf solitary, or rarely 2, linear or narrowly lanceolate, plicate, 13-30 × (0.4-)1-2 cm, gradually tapering at base into an indistinct petiole-like stalk 3-5(-8) cm, apex acuminate. Inflorescence 25-67 cm, with 2 or 3 tubular sheaths below middle; rachis 4-15.5 cm, laxly few to subdensely many flowered; floral bracts narrowly lanceolate, 2.5-5 mm. Flowers yellowish brown to pale yellow, lip white with purple spots; pedicel and ovary 8-12 mm. Sepals narrowly oblong, 7-9 × 1.5-2 mm, apex slightly obtuse; lateral sepals slightly falcate. Petals narrowly oblong, slightly falcate, 7-8 × 1.5-1.8 mm, apex acute; lip oblong-obovate, 6.5-8.5 × 3.5-5 mm, shortly clawed at base, 3-lobed below middle; lateral lobes slightly incurved, linear, ca. 3 × 0.7 mm, apex obtuse; mid-lobe subobovate, 5.5-7 × 3-5.5 mm, apex obtuse-rounded and irregularly incised; disk with a pair of thick lamellae, extending from base to midway along mid-lobe; lamellae to 3.5 mm. Column 4-5 mm, base thickened. Capsule oblong, ca. 15 × 7 mm. Fl. Jun-Jul, fr. Sep-Oct. 2n = 48.
Forests, forest margins, thickets, grassy places, shaded places along valleys; 1000-3000 m. Gansu, Guizhou, Heilongjiang, Henan, Hunan, Jiangxi, Jilin, Liaoning, Sichuan, Taiwan, NE and NW Yunnan [Japan, Korea, Russia (Far East)].