Distribution: Occurring west of the Cascades crest in Washington; British Columbia to California and Nevada; occurring in central U.S and eastern North America.

Habitat: Moist, disturbed ground along lakes, ponds, roadsides and near gardens.

Flowers: June-August

Origin: Introduced from Eurasia

Growth Duration: Perennial

Conservation Status: Not of concern

Pollination: Bees, flies

Prostrate, glabrous, perennial herbs, the creeping stems rooting at the nodes, covered with tiny red dots.

Leaves opposite, short-petiolate, nearly orbicular to oval, 1-3 cm. long and broad.

Flowers single in the leaf axils on pedicels 1-3 cm. long; calyx united only at the base, the 5 lobes 6-9 mm. long, cordate-lanceolate; corolla divided nearly to the base, rotate, yellow, the 5 lobes 8-12 mm. long, with glandular hairs on the margins and on the base of the upper surfaces; stamens 5, exerted, opposite the corolla lobes; filaments glandular-pubescent, several times as long as the anthers, unequal, united at the base;

Capsule opening by 5 valves.