Amesia thunbergii (A. Gray) A. Nelson & J. F. Macbride; Arthrochilium thunbergii (A. Gray) Szlachetko; Epipactis gigantea Douglas var. manshurica Maximowicz ex Komarov; E. gigantea var. thunbergii (A. Gray) M. Hiroe; E. thunbergii var. manshurica (Maximowicz ex Komarov) Tang & F. T. Wang; Helleborine chinensis Soó; H. thunbergii (A. Gray) Druce; Limodorum thunbergii (A. Gray) Kuntze.

Plants 20-30 cm tall. Rhizome elongate. Stem glabrous, with 2-4 sheaths toward base. Leaves 6-8, spreading, ovate-lanceolate, 5-13 × 1.2-3 cm, glabrous, base amplexicaul, apex acuminate or cuspidate-acuminate. Rachis 3-5 cm, glabrous, laxly 3-10-flowered; floral bracts foliaceous, ovate-elliptic, lower ones exceeding flowers. Flowers spreading, resupinate, pale green or yellow-green; lip white with purple venation on side lobes and purple markings on disk; ovary and pedicel ca. 15 mm, glabrous. Dorsal sepal ovate-elliptic, ca. 11 × 4 mm, apex acute; lateral sepals ovate-elliptic, ca. 10 × 3 mm, apex acute. Petals broadly ovate, slightly oblique, 7-10 × ca. 5 mm, apex acute; lip ca. 10 mm, with a short mesochile connecting hypochile and epichile; hypochile cymbiform, ca. 3 × 3 mm, with erect lateral lobes ca. 4 × 2 mm; mesochile sometimes inconspicuous, oblong, 1-2 × ca. 2 mm; epichile ovate-orbicular, ca. 3 × 3 mm, margin slightly undulate, with a pair of low keels. Column ca. 3 mm excluding anther, relatively thick. Fl. Jun-Jul. 2n = 40.

E Zhejiang [Japan, Korea].