Perennial by short rhizomes, forming large clumps; stems 1.5-4 dm, sparsely villous; lvs chiefly basal, lanceolate to narrowly oblong or oblanceolate, pinnately lobed into several oblong or ovate, crenate segments; lower lvs on petioles often longer than the blade, the cauline progressively reduced and the upper subsessile; spikes commonly solitary, 3-5 cm, in fr to 20 cm, the bracts oblanceolate, usually toothed only at the tip; cal very oblique, the 2 lateral halves entire, separated by a short cleft above and a deeper one below; cor yellow to purple, 18-25 mm, the galea with 2 slender teeth just below the rounded tip, the lower lip shorter than the galea; 2n=16. Upland woods and prairies; Que. and Me. to Man., s. to Fla. and Tex.; also Colo. to n. Mex. Apr.-June.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
This species prefers a dry, sandy, and slightly acid soil, although it is often found in clayey soil, and I once found it well established in a marsh. It usually grows on white oak slopes, sometimes with beech, along streams. It is rather frequent in the lake area becoming less frequent southward and our map shows a large, open area in the southwestern part of the state. The flowers are usually yellowish, but plants with reddish flowers are not rare.