Stems mostly several, 3-7 dm; stipules connate opposite the lf-base; lfls 15-21, oblong to elliptic or lanceolate, those of the principal lvs 15-30 נ5-10 mm; racemes secund, 5-10 cm, on peduncles 8-15 cm; fls 12-16 mm, purple, seldom white; keel surpassing the standard and wings; fr with (1)2-5 flat joints each 5-9 נ3.5-6 mm; 2n=14. River-banks, hills, and ledges, in moist soil; Siberia and boreal N. Amer., s. to Me., n. Vt., n. Mich., Man., Wyo., and B.C. June-Aug. Our plants are var. americanum Michx. (H. boreale, misapplied)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.