Stem leafy, 4–10 dm, hirsute; lvs elliptic-oval, 1–2 dm, half as wide, clasping, strongly ribbed, hairy; fls 1–3; sep white, round-oval, obtuse, 2.5–4 × 1–3 cm, the lower 2 completely united; lateral pet white, flat, oblong, nearly as long as the sep but much narrower; lip 3–4 cm, white or suffused with pink, irregularly streaked with rose or purple outside and marked with purple inside; 2n=20. Swamps, bogs, and wet woods; Nf. and Que. to N.D., s. to N.C., Ga., and Mo. June, July. (C. hirsutum)