Annual or biennial; stems 10-15 dm, softly retrorse-hairy; lvs broadly ovate to rotund in outline, deeply 3-parted, each division laciniately toothed or cleft; lvs subtending the fls smaller, more deeply lobed into narrow segments; bracts half to fully as long as the weakly 10-nerved cal-tube; cor 10-14 mm, with a ring of hairs inside, the upper lip densely but finely hairy; 2n=20. Native of Asia, widely intr. in tropical Amer. and occasionally found in waste places in our range. May-Sept.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
