9. Rorippa curvipes Greene, Pittonia. 3: 97. 1896. (as Roripa).
Cardamine palustris (Linnaeus) Kuntze var. jonesii Kuntze; Radicula curvipes (Greene) Greene; R. integra (Rydberg) A. Heller; R. sinuata (Nuttall) Greene var. integra Jepson; R. sinuata var. truncata Jepson; R. underwoodii (Rydberg) A. Heller; Rorippa curvipes var. integra (Rydberg) Stuckey; R. curvipes var. truncata (Jepson) Rollins; R. integra Rydberg; R. obtusa (Nuttall) Britton var. integra (Rydberg) Victorin; R. truncata (Jepson) Stuckey; R. underwoodii Rydberg
Annuals or, rarely, perennials; (short-lived, terrestrial or of wet habitat, not submerged); glabrous or hirsute, (trichomes cylindrical). Stems (few to several from base), usually ascending, decumbent, or prostrate, rarely erect, branched distally, 1-4.2(-5) dm, (hirsute proximally). Basal leaves not rosulate; blade margins pinnatifid. Cauline leaves shortly petiolate or sessile; blade oblong or oblanceolate to obovate, (terminal lobe oblong), (2-)3.5-10(-12) cm × (5-)10-30(-37) mm, (lateral lobe smaller than terminal), base usually auriculate, rarely amplexicaul, margins: proximal pinnatifid or sinuate, distal dentate or entire, (surfaces sparsely pubescent). Racemes elongated. Fruiting pedicels divaricate-ascending to horizontal, straight or recurved, (1.2-) 1.7-5(-8) mm. Flowers: sepals erect, oblong, 0.8-1.8 × 0.5-1 mm; petals (erect), yellow, oblanceolate to spatulate, 0.5-1.8 × 0.2-1 mm; median filaments 0.9-1.3 mm; anthers ovate, 0.3-0.5 mm. Fruits silicles or siliques, curved, ovoid to pyriform, 2-8(-8.8) × (0.5-) 1-2.5 mm; valves glabrous; ovules (20-)30-80 per ovary; style 0.3-1 mm. Seeds biseriate, brown, cordiform, 0.5-0.7 mm, colliculate. 2n = 16.
Flowering May-Sep. Muddy shores of lakes and ponds, stream beds and banks, edges of cultivated fields, wet roadside, meadows, seepage areas, ditches, creeks, gravel bars; 100-3500 m; Alta., B.C., Sask.; Ariz., Ark., Calif., Colo., Idaho, Ill., Kans., Mich., Minn., Mo., Mont., Nebr., Nev., N.Mex., N.Dak., Oreg., S.Dak., Tex., Utah, Wash., Wyo.; Mexico (Coahuila).