二叶舌唇兰 er ye she chun lan

Orchis chlorantha Custer, Neue Alp. 2: 400. 1827; Gymnadenia chlorantha (Custer) Ambrosi; Habenaria chlorantha (Custer) Babington; H. subulifera W. W. Smith; Platanthera sigmoidea Maekawa; P. subulifera (W. W. Smith) Schlechter.

Plants 30-54 cm tall. Rootstock tuberous, ovoid-fusiform, 2-4 × 0.8-1.5 cm. Stem erect, with a tubular sheath at base, 2-leaved. Leaves basal, subopposite, spatulate-elliptic or oblanceolate-elliptic, 10-20 × 3-8 cm, gradually contracted and sheathing at base, apex obtuse or acute. Peduncle slender to robust, with 1-4 scattered, lanceolate bracts; rachis 7-23 cm, laxly to subdensely 9-32-flowered; floral bracts lanceolate, 10-22 mm, basal ones exceeding ovary, apex acuminate. Flowers fragrant, greenish white or white; pedicel and ovary arcuate, cylindric, 12-18 mm. Dorsal sepal erect, forming a hood with petals, ovate to orbicular-cordate, cymbiform, 5-7 × 5-6 mm, glabrous, 5-veined, apex obtuse; lateral sepals spreading, ovate, oblique, 7.5-8 × 4-4.5 mm, glabrous, 3-5-veined, apex acute. Petals narrowly ovate-lanceolate, oblique, 5-6 × 2.5-3 mm, 1-3-veined, apex acute; lip spreading to pendulous, ligulate, gradually tapering toward apex, 8-13 × ca. 2 mm, entire, apex obtuse; spur pendulous to spreading horizontally or sometimes arching upward, clavate-cylindric, 16-36 mm, exceeding ovary, conspicuously thickened toward apex, apex obtuse. Column stout; staminodes conspicuous; anther locules divergent; pollinia ellipsoid, with slender caudicles and orbicular viscidia; rostellum broad, tapelike; stigma lobes confluent, concave, lying directly below rostellum. Fl. Jun-Aug, fr. Jul-Sep. 2n = 42.

Forests on slopes, grasslands; 400-3300 m. Gansu, Hebei, Heilongjiang, Henan, Jilin, Liaoning, Nei Mongol, Qinghai, Shaanxi, Shandong, Shanxi, Sichuan, Xizang, Yunnan [Japan, Korea, Russia; W Asia, Europe].