A European sp. with deeply pinnatifid lvs, and with the lower segment of the fr dilated into projecting teeth at the joint, is occasionally adventive about Atlantic seaports and appears to be established on beaches in the Chesapeake Bay region.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
