Distribution: Introduced in scattered locations across Washington, moreso in western lowlands; occurring in much of eastern North America, where it is considered invasive.
Habitat: Somewhat moist disturbed areas.
Origin: Introduced from Europe
Conservation Status: Not of concern
Perennial herbs with milky juice, the stems more or less prostrate, rooting, nearly glabrous.
Leaves opposite, ovate to elliptic, 2.5-5 cm. long, short-petiolate, rather leathery.
Flowers solitary in the leaf axils, on long pedicels; calyx divided nearly to the base, the 5 lobes linear; corolla blue-violet, with long, narrow tube and 5 widely-spreading, truncate to rounded lobes, 25-30 mm. broad; tube about 2 cm. long, crested and hairy in the throat; stamens 5, attached below the throat, the filaments short; style elongate, the stigma ovoid, tapering to a truncate apex; ovary superior.
Follicles elongate, forked.