Plants 1-2 m, widely branched, glabrous and glaucous; stipules lanceolate, 5-10 mm, some usually persisting until anthesis; petioles 6-12 mm; lfls narrowly obovate to oblanceolate, 3-6 cm; racemes solitary or few, erect, 2-6 dm; bracts lance-ovate, caducous; pedicels 4-10 mm; fls white or with a tinge of purple on the standard, 18-25 mm; cal 8 mm, densely pubescent within; pods black, drooping, ellipsoid-oblong, firm and thick-walled, 2.5-4 cm נ8-12 mm, abruptly narrowed to a short beak; stipe well exserted; 2n=18. Prairies and open upland woods; O. and s. Mich. to Minn., Neb., and Tex., and e. in the coastal states to Fla. and N.C.; locally (intr.?) in w. N.Y. June, July. Ours is var. lactea. (B. leucantha)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.