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Northern Prairie Wildlife Research Center

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Aquatic and Wetland Vascular Plants of the Northern Great Plains

22. Brassicaceae, the Mustard Family

4. Rorippa Scop. -- Yellow cress

3. Rorippa curvipes Greene

Annual or possibly a shortlived perennial, usually over 3 dm tall; stems prostrate to decumbent or occasionally erect, 1-5 dm long, single or branched from the base, sparingly to moderately hirsute in the lower portion. Leaves short-petioled to sessile, auriculate and clasping to nonauriculate and nonclasping, the blades oblong, obovate, spatulate or oblanceolate, mostly 3-10 cm long, 0.5-2(3) cm wide, glabrous on both surfaces or sparingly hirsute above, obtuse to acute at the tip, the margin entire to irregularly toothed or repand, or the lower leaves sometimes pinnately divided to the midrib, the lobe margins entire to slightly toothed, the terminal lobe acute to obtuse. Racemes terminal and axillary, all about the same age or the siliques somewhat older on the lower portion of the terminal raceme. Sepals greenish, 0.8-1.7 mm long, caducous; petals yellow, fading to whitish when dried, 0.5-1 mm long, mostly shorter than the sepals. Siliques short-cylindrical, 1.4-5 mm long, 1.5-2.5X longer than wide, straight or curved upward and inward toward the raceme axis, the valves glabrous; pedicels ascending or strongly recurved, sometimes so that the raceme appears 1-sided, mostly 2-6 mm long. Jul--Aug. Shores, stream banks and mud flats; uncommon and scattered in ND, SD, MT and WY; (ND and Sask. to WA, s to KS, NM, AZ and CA; apparently intro. in WI). R. obtusa (Nutt.) Britt., in part.
GIF- Distribution Map

Map key

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