Distribution: Distributed on both sides of the Cascades in Washington; widely distributed throughout North America.
Habitat: Riparian zones and other wet areas.
Origin: Introduced from Europe
Conservation Status: Not of concern
Aquatic, glabrous perennial, the stems often floating and rooting at the nodes, fleshy, limp, 1-5 dm. long, only the tip erect.
Leaves alternate, pinnate, the 3-11 segments ovate to lanceolate, the terminal lobe much the largest.
Inflorescence of flat-topped, bractless racemes, elongate in fruit; pedicles 8-20 mm. long, spreading; sepals 4, whitish, the outer pair saccate at the base; petals 4, white to purplish-veined and -tinged, broadly spatulate, 3-4 mm. long; stamens 6; style stout, 1 mm. long, the stigma bi-lobed.
Siliques mostly about 15 mm. long and 2 mm. broad, spreading, curved, and somewhat erect; seeds in 2 series.