Rhizomatous perennial; stems trailing or climbing to 2 m, broadly winged, 5-10 mm wide; stipules ovate or lanceolate, with a basal lobe, 2.5-4 cm; petiole broadly winged; lfls 2, lanceolate to elliptic, 4-8 נ1-3 cm; peduncles 10-20 cm, with a raceme of 4-10 anthocyanic or white fls 1.5-3 cm; cal-lobes very unequal; fr 6-10 cm, 10-15-seeded; 2n=14. Native of s. Europe, tending to escape from cult. esp. toward the s. part of our range. June-Aug.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.