Perennial from a fusiform taproot, often branched from the base, erect, 3-8 dm; lfls narrowly oblong or elliptic to lance-linear, 5-7 cm, gradually narrowed to an obtuse tip, glabrous to thinly pubescent; peduncles ascending, much exceeding the subtending lvs; racemes 2-6 cm; fls blue, 6-7 mm, subtended by deciduous bracts; cal ±hirsute, the tube 1.5-2 mm, the lobes triangular, pointed, the upper about equaling the tube, the lower longer; fr suborbicular, 4-5 mm; 2n=22. Dry or moist open woods and prairies. May, June. (Psoralea p.) Two well marked vars., intergradient s. of our range:
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.