Distribution: Occurring chiefly east of the Cascades crest in Washington; widely distributed throughout much of North America.

Habitat: In or along slow-moving streams in the lowlands.

Flowers: June-September

Origin: Introduced from Europe

Conservation Status: Not of concern

Glabrous, short-lived perennial from fibrous roots, the stems usually erect, 2-10 dm. tall.

Leaves opposite, sessile and clasping, elliptic-ovate to elliptic-oblong, 2-10 cm. long and 0.7-5 cm. wide, sharply serrate to entire.

Inflorescence of many-flowered racemes on long peduncles arising in the leaf axils; calyx of 4 highly variable sepals; corolla blue, rotate, 4-lobed, the upper lobe the largest, about 5 mm. wide; style 1.5-2.5 mm. long; pedicels up-curved, 3-8 mm. long; stamens 2.

Capsule swollen, 2.5-4 mm. high and wide, scarcely notched.