Stems yellow, greenish, or purplish brown, base strongly thickened, bulbous. Inflorescences: racemes lax, 11-46 × 1-2.5 cm. Flowers 5-26, inconspicuous; perianth open or closed; sepals and petals reddish purple to brown, often suffused with green, broadly lanceolate, 1-2-veined; lateral sepals strongly curved upward and directed forward, 3-4.5 mm; petals 2.5-3.8 mm, connivent with dorsal sepal to form hood over column, or sepals and petals connivent to produce closed flower; lip white, often spotted with purple, ovate to orbiculate-quadrangular, unlobed, 2.7-4.6 ×1.8-3.7 mm, thin, with 2 distinct basal lamellae, margins entire to erose-fringed; column white basally, often purple apically, 1.9-2.5 mm, straight or curved toward lip, with 2 distinct auricles in open-flowered plants; ovary 2.5-5 mm; mentum inconspicuous. Capsules broadly ellipsoid, 5.5-8 × 3.5-5 mm.
Stem 1-2 dm, with a bulbous-thickened white base, otherwise purple to brown, or greenish above; infl 3-6 cm; fls 5-15; sep and lateral pet extending forward over the column, oblong, 3-4.5 mm, yellowish to purplish-green or dark purple; lip declined, short-clawed or nearly sessile, expanded above into a rotund blade 3-4 mm, white, usually purple-margined with 2 purple spots, entire or finely erose, often emarginate. Open woods; Me. and Vt. to N.Y., s. Mich., and s. Minn., s. to Fla. and Mex. Aug.-Sept.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.