Cypripedium bouffordianum Yong H. Zhang & H. Sun; C. orientale Sprengel.

Plants 15-25 cm tall, with a slender, creeping rhizome. Stem erect, pubescent and glandular hairy, with several sheaths at base and 2 or rarely 3 leaves above. Leaves subopposite or occasionally alternate, at or above middle of plant; blade often turning black or blackish when dried, elliptic, ovate, or ovate-lanceolate, 5-12 × 2.5-4.5(-6) cm, abaxial veins sparsely pubescent or subglabrous, apex acute or acuminate. Inflorescence terminal, with 1 flower; peduncle densely pubescent and glandular hairy; floral bracts foliaceous, ovate-lanceolate, usually 1.5-3 cm, minutely ciliate, apex acute or acuminate; pedicel and ovary 1-1.5 cm, with glandular hairs. Flower white with purplish red or brownish red markings. Dorsal sepal ovate-elliptic or broadly ovate-elliptic, 1.5-2.2 × 1.2-1.6 cm, often sparsely puberulent toward abaxial base, apex acute or shortly acuminate; synsepal narrowly elliptic, 1.2-1.8 × 0.5-0.6 cm, apex shallowly 2-lobed. Petals often subspatulate or pandurate, 1.3-1.8 × 0.5-0.7 cm, hairy toward adaxial base, apex often slightly dilated and rounded; lip deeply pouched, pitcher-shaped, ca. 1.5 × 1.5 cm, lacking an incurved apical margin, with a broad mouth, inner bottom hairy. Staminode ovate-elliptic, 4-5 × 2.5-3 mm, abaxially broadly keeled, adaxially minutely longitudinally ridged, apex emarginate or subtruncate. Capsule pendulous, nearly narrowly ellipsoid, ca. 2.5 cm × 8-10 mm, puberulent. Fl. May-Jul, fr. Aug-Sep. 2n = 20, 30.

Cypripedium bouffordianum is evidently an albino form of C. guttatum. It is very similar in habit and flower structure to C. guttatum but lacks any purple-red or brown-red markings on the flower.

Cypripedium yatabeanum Makino (Bot. Mag. (Tokyo) 13: 91. 1899; C. guttatum subsp. yatabeanum (Makino) Hultén) was described from Japan and later reported from Heilongjiang and Jilin by P. Y. Fu and S. Z. Liu (in P. Y. Fu, Clavis Pl. Chinae Bor.-Orient., ed. 2, 895. 1995). It differs from C. guttatum by having dark brown spots on sepals, petals, and lip, and a larger lip more than 2 cm. However, the present authors are unaware of any Chinese specimens.

Forests, thickets, grasslands; 500-4000 m. Hebei, Heilongjiang, Jilin, Liaoning, Nei Mongol, Ningxia, Shaanxi, Shandong, Shanxi, Sichuan, Xizang, NW Yunnan [Bhutan, Korea, Russia (Far East, Siberia); Europe, North America].