Perennial; stems twining, 1-3 m; lfls broadly rhombic-ovate; racemes to 3 dm; fls purple or white, 1.5-2.5 cm; fr 3-8 נ1.5-2 cm; 2n=20, 22, 24. Native of Asia, rarely escaped from cult. as far n. as N.Y.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.