Plants 7-33 cm. Leaves: blades 2.7-11 × 1.2-8 cm. Inflorescences: floral bracts lanceolate to linear, 5-15 × 1-5 mm, apex acute to acuminate. Flowers showy; sepals white to pale magenta, ovate to elliptic-oblong, 6-10 × 3-4 mm; petals white to pale magenta, ovate to lance-oblong, 5-6 mm, less than 1/2 as wide; lip white, prominently magenta-spotted, rarely with broad, longitudinal, reddish bars, ovate in outline, 6-9 × 4-8 mm, lateral lobes spreading, spur conspicuous, 2/3 as long as to equaling lip, slender. Capsules erect, ellipsoid. 2n = 42. Flowering Jun--Jul. Moist, often calcareous coniferous forests, thickets, fens, tundra; 0--1200 m; Greenland; Alta., B.C., Man., N.B., Nfld. and Labr., N.W.T., Nunavut, Ont., Que., Sask., Yukon; Alaska, Maine, Mich., Minn., Mont., N.Y., Vt., Wis., Wyo.
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.