Stems erect, somewhat woody, to 1.5 dm, with numerous long virgate branches, very leafy; petioles 2-5 mm; lfls ascending or erect, linear-cuneate, 10-25 mm, truncate and mucronate at the tip, glabrous above, sericeous beneath; branches sulcate, hairy on the angles; fls mostly solitary (2-3) in the upper axils, white marked with purple or pink, 7-9 mm, the wings and keel about equal; cal sericeous, the lobes lance-subulate, 3 mm, the 2 upper connate about half their length; fr oval, 3 mm; 2n=20. Native of e. Asia, cult. in se. U.S. and now planted and established along roadsides and in disturbed sites in the s. part of our range, n. to N.J., L.I., and even Mich.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.