Description from Flora of China
Cypripedium arietinum Franchet (1885), not R. Brown (1813).
Plants 12-30 cm tall, with a stout, rather short rhizome. Stem erect, pubescent, with several sheaths at base and 3 or rarely 2 or 4 leaves above. Leaf blade elliptic to narrowly elliptic-lanceolate, 4.5-6 × 1-3.5 cm, abaxial veins occasionally puberulent, adaxially subglabrous, apex acute or shortly acuminate. Inflorescence terminal, with 1 flower; peduncle slender, pubescent; floral bracts foliaceous, elliptic-lanceolate or lanceolate, 2-3 × 0.7-0.8 cm, slightly ciliate, apex acuminate or acute; pedicel and ovary 1.5-2.5 cm, densely pubescent. Flowers relatively small; sepals and petals chocolate-brown or greenish brown, petals usually with a white margin; lip and staminode white, tinged with pink. Dorsal sepal ovate-lanceolate, 1.6-1.8 × 0.7-0.8 cm, slightly hairy at base, minutely ciliate, apex acute; lateral sepals free, linear-lanceolate, 1.6-1.8 × 0.2-0.3 cm, slightly hairy at base, apex acuminate or acute. Petals linear, 1.6-2.1 × 0.1-0.2 cm, pubescent toward adaxial base; lip deeply pouched, obconic, slightly oblique, 1.6-2.4 × ca. 1 cm, pubescent around mouth, inner bottom hairy, obtusely tipped. Staminode obovate or square-obovate, 5-6 mm, abaxially carinate, with a very short stalk at base. Capsule narrowly ellipsoid, ca. 2 cm × 5-6 mm, ridged, sparsely pubescent along ridges. Fl. Apr-Jun, fr. Jul. 2n = 20.
Forests, forest margins, thickets, stony and grassy slopes; 2000-3600 m. W Hubei, W Sichuan, SE Xizang, C and NW Yunnan [Myanmar].