Lf 1, elliptic to ovate or obovate, 4-11 cm; scape 1-2.5 dm, slender; bracts lance-linear, 6-15 mm; sep and lateral pet pale purple to white, oblong-obovate, 5-8 mm, the pet slightly narrower than the sep; 2 lateral pet and upper sep connivent, the lateral sep spreading; lip white, spotted with pale purple, 6-9 mm, 3-lobed, the lateral lobes short-ovate, ascending, the terminal one triangular, notched at the summit; spur much shorter than the lip; 2n=42. Wet woods and swamps; Greenl. to Alas., s. to Que., n. N.Y., Mich., Minn., and B.C. June, July. (Amerorchis r.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.