Distribution: Weedy introduction across southern Canada and the northern tier of states in the United States.
Habitat: Moist to dry woods, roadsides, fields, waste areas.
Flowers: May - July
Origin: Introduced from Eurasia
Conservation Status: Not of concern
Nearly glabrous perennial, the stems branching, ribbed, to 10 dm. tall.
Basal leaves in a rosette; cauline leaves alternate, up to 35 cm. long with petioles 2-10 cm. long; leaf blades deeply 5-9 lobed, the margins irregularly dentate.
Inflorescence a terminal umbel, the peduncle 2-10 cm. long, pedicles 5-35 mm. long; sepals 2, distinct, up to 1 cm. long; petals 4, bright yellow, obovate to oblong, up to 2 cm. wide; flowers 20-25 mm. in diameter; stamens 12-many; style 1 mm. long.
Capsules linear to narrowly oblong, 2-5 cm. long, glabrous