Plant: Annual, 0.5-2 m, taprooted; herbage glabrous, glaucous, anise-scented; stem erect, branched, hollow, ribbed Leaves: mostly cauline; petiole 5-6 cm; blade 12-35 cm, oblong to obovate, pinnately dissected, segments 4-20 mm, thread-like Inflorescence: umbels compound, peduncled; bracts, bractlets 0; rays, pedicels many, slender, subequal, spreading or spreading-ascending Flowers: many, small; calyx lobes 0; petals 5, wide, yellow, tips narrowed; tamens 5; pistil 1, ovary inferior, 2-chambered, generally with a ± conic, persistent projection or platform on top subtending 2 free styles Fruit: 2 dry, 1-seeded halves that separate from each other but generally remain attached for some time to a central axis, 2-4.5 mm, ovate, compressed front-to-back, glabrous; ribs unequal, marginal narrowly winged, others thread-like; oil tubes per rib-interval 1; fruit axis divided to base; Seed: face ± flat Misc: Disturbed places; generally < 1000 m.