Erect, sparsely hairy annual 2-5 dm, branched above; basal and lower cauline lvs pinnately dissected into linear segments; upper cauline lvs broadly ovate to subrotund, entire, deeply cordate, the rounded auricles about as long as the rest of the blade and usually overlapping; sep firm, broadly oval, 1-1.3 mm; pet narrowly spatulate, yellow, 1-1.5 mm; stamens 6; fr rhombic-elliptic, 4 נ3 mm, obscurely retuse; style about as long as the notch; 2n=16. Native of Europe, well established as a weed in w. U.S., e. to Mich. and O. and occasionally elsewhere in our range. May, June.Erect, sparsely hairy annual 2-5 dm, branched above; basal and lower cauline lvs pinnately dissected into linear segments; upper cauline lvs broadly ovate to subrotund, entire, deeply cordate, the rounded auricles about as long as the rest of the blade and usually overlapping; sep firm, broadly oval, 1-1.3 mm; pet narrowly spatulate, yellow, 1-1.5 mm; stamens 6; fr rhombic-elliptic, 4 נ3 mm, obscurely retuse; style about as long as the notch; 2n=16. Native of Europe, well established as a weed in w. U.S., e. to Mich. and O. and occasionally elsewhere in our range. May, June.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.