Erect or climbing perennial to 10 dm; stipules small, half-sagittate or ovate; lfls 4-9 pairs, ovate to ovate-oblong, entire, 1-2.5 cm; fls 2-6 in subsessile axillary clusters, blue- violet to white, 8-15 mm; cal distinctly irregular, the tube 4-5 mm, brown-villous, the lobes abruptly narrowed above a broadly triangular base into a slender tip, the lower half as long as the tube, the upper much shorter; fr 2-3.5 cm נ5-8 mm, 3-7-seeded, with smooth sutures; 2n=14. Native of Europe, intr. here and there in our range, especially northward.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.