Rorippa sylvestris (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 - Erect perennial 2–6 dm, usually branched above, glabrous or sparingly hirsute on the lower part of the stem; basal rosettes present in young plants; cauline lvs slender-petiolate, oblong, deeply pinnatifid or divided into numerous oblong or obovate segments, the lower lvs to 2 dm, more than 2 cm wide, the upper progressively reduced, the segments mostly acute, sharply or angularly toothed or in depauperate pls subentire; pet 4–5 mm, twice as long as the sep; mature pedicels widely divergent or somewhat deflexed, often arcuate, 5–10 mm; frs nearly straight, 10–15 × 1.5 mm, the style 0.5–1 mm; seeds often wanting; 2n=32, 40, 48. Native of Eurasia, intr. in wet soil nearly throughout our range. May–Aug. (Radicula s.)
creeping yellow cress