Erect, branched above, to 12 dm; lvs several pairs, ovate or ovate-oblong, acuminate, glabrous, the lower 1-2 dm, on petioles to 1 cm, the upper progressively smaller and the uppermost commonly sessile; panicles 1-3 dm, divergently branched, often compound with branches from the uppermost lf-axils; fls all paired at the minutely bracteate nodes of the infl; cal 2.5-4 mm at anthesis, weakly bilabiate, 8 mm in fr; cor 12-15 mm, the lower lobe oblong, nearly as long as the tube; stamens 2; 2n=50. Rich woods; Que. to Mich. and s. Wis., s. to Fla. and Ark. July-Sept.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Throughout the state in dry, rich woods although we have but one record from the northwestern counties. The thickened, hard rootstock is much used in medicine for kidney and urinary disorders.
