Distribution: Occurring in scattered locations on both sides of the Cascades crest in Washington; British Columbia to California, east across much of North America to the Atlantic Coast.
Habitat: Roadsides, fields, wastelots, and other disturbed open areas.
Origin: Introduced from Asia
Conservation Status: Not of concern
Annual, 0.5--2 m tall, taprooted; herbage glabrous, glaucous, anise-scented; stems erect, branched, hollow.
Leaves generally cauline, alternate; petiole 5-6 cm long; blade 12-35 cm, oblong to obovate, pinnately dissected, segments 4-20 mm, thread-like.
Umbels compound, peduncled; bracts, bractlets 0; rays, pedicels many, slender, equal length, spreading or spreading-ascending; no calyx lobes; petals wide, yellow, tips narrowed.
Mericarps 2-4.5 mm, ovate, compressed front-to-back, glabrous; ribs unequal, marginal narrowly winged, others thread-like; oil tubes 1 per rib-interval; fruit axis divided to base; seeds flat-faced.