Description from Flora of China
Anoectochilus elwesii (C. B. Clarke ex J. D. Hooker) King & Pantling; A. purpureus (C. S. Leou) S. S. Ying; Cystopus elwesii (C. B. Clarke ex J. D. Hooker) Kuntze; Odontochilus purpureus C. S. Leou.
Plants autotrophic, 15-25 cm tall. Stem ascending or erect, somewhat robust, ca. 3 mm in diam., 6- or 7-leaved. Leaves abaxially pale red or pale green, adaxially deep green to dark greenish purple and sometimes with 3 reddish veins, ovate to ovate-lanceolate, 1.5-5 × 1-3 cm, apex acute; petiole-like base and tubular sheath 0.5-2 cm. Peduncle 8-11 cm, with 1-3 sheathing sterile bracts, pubescent; rachis 1-6 cm, laxly 2-4-flowered, pubescent; floral bracts ovate, ca. 5 mm, much shorter than ovary, outer surface pubescent, apex mucronate. Flowers resupinate; ovary and pedicel twisted, cylindric-fusiform, ca. 13 mm, pubescent. Sepals green or white, tinged purplish red toward apex, outer surface pubescent, 1-veined; dorsal sepal forming a hood with petals, with 2 broad purplish red stripes, ovate, cymbiform, ca. 7 × 4 mm, apex acuminate; lateral sepals ovate, oblique, ca. 10 × 6 mm, saccate at base. Petals white, ovate, strongly oblique, falcate, ca. 7 × 4 mm, 1-veined, apex acuminate; lip white, Y-shaped, ca. 15 mm; hypochile slightly dilated, shallowly bisaccate, ca. 3.5 mm, containing a central longitudinal septum and 1 fleshy, subsquare callus on either side; mesochile dark purple, 5-7 mm, with a fimbriate flange along either margin; flanges composed of 4 or 5 filaments; epichile transversely dilated, ca. 12 × 14 mm, 2-lobed; lobes diverging widely, suboblong, ca. 10 × 5 mm, margin slightly undulate, apex truncate. Column ca. 4 mm, stout, with 2 suboblong, lamellate wings; anther narrowly ovoid, ca. 4 mm; pollinia clavate, ca. 3 mm, attached to a narrowly lanceolate viscidium ca. 1.5 mm; rostellum erect, small, remnant furcately bifid; stigma lobes separate, suborbicular, large. Fl. Jul-Aug.
Damp places in evergreen broad-leaved forests, bamboo forests, valleys; 300-1500 m. Guangxi, Guizhou, Sichuan, C Taiwan, Yunnan [Bhutan, NE India, N Myanmar, Thailand, N Vietnam].