Distribution: Southwestern Washington; Washington south to Oregon, from the Willamette Valley to the Coast.

Habitat: Lowland ponds and marshes.

Flowers: April-May

Conservation Status: Not of concern

Pollination: Bees, flies

Glabrous annual with slender rhizomes that are enlarged and tuberous at the tips; stems simple, procumbent, often rooting at the nodes, 2-4 dm. long.

Leaves alternate, mostly cauline, pinnate, the lateral pinnae 6-10, sessile, lanceolate to oblanceolate, mostly entire, the terminal leaflet considerably larger, 2-3.5 cm. long, few-toothed.

Inflorescence of bractless, few-flowered racemes, the pedicles spreading-ascending, 1-2 cm. long; sepals 4, 3-4.5 mm. long; petals 4, white, 8-11 mm. long; stamens 6; style 4-6 mm. long.

Siliques spreading to erect, 2-4 cm. long and about 1.5 mm. broad.