Plants erect, 10–35 cm. Leaves 3–4, along middle portion of stem, spiraled to alternate, ascending to spreading; blade narrowly elliptic to ovate-lanceolate or oblong, 5–11 × 1.3–3.5 cm. Flowers usually solitary (rarely 2 in forma biflorum P. M. Brown); sepals green with reddish brown markings; dorsal sepal broadly elliptic to ovate-lanceolate, 15–25 × 5–10 mm; lateral sepals distinct, 12–20 × 1.5–4 mm; petals somewhat spreading, same color as sepals, somewhat spirally twisted, linear- to linear-lanceolate, 11–24 × 1–2 mm; lip white with green apex, usually with extensive reddish reticulations often merging toward apex, adaxially swollen near middle, 10–16 mm, apex abruptly deflected downward, orifice basal, 7–12 mm; staminode suborbicular. 2n = 20.
"Stem slender, 1–4 dm, thinly hairy, with 2–3 sheathing scales below and 3–5 sessile lvs above the middle; lf-blades lanceolate to elliptic, often folded, 5–10 cm, finely ciliate, otherwise glabrous; fl solitary; sep and lateral pet 1.5–2.5 cm, greenish-brown, the upper sep lanceolate, the lower 2 sep separate, linear, the lateral pet lance-linear; lip whitish, strongly red-veined, 1.5–2.5 cm, prolonged downward to form a conical pouch. Moist, usually acid soils in coniferous woods; Que. to Man., s. to Mass., N.Y., Mich. and Minn. May, June."