Rorippa palustris (L.) Besser
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Taprooted annual or biennial, erect, to 1 m, the taller pls commonly much-branched; lvs lanceolate to oblong-obovate, at least the lower pinnatifid; pet 1.5–2.5 mm, about equaling the sep, mature pedicels widely spreading, 3–7 mm; frs 2.5–9 mm, to twice as long as the pedicels; middle cauline lvs generally distinctly winged toward the base and auriculate, so that the lf appears ± sessile; 2n=32. (R. islandica, misapplied) R. palustris is circumboreal, with 3 vars. in our range.