Distribution: Introduced, common in eastern United States, but infrequent in the Pacific Northwest.
Habitat: Waste places.
Flowers: June - August
Conservation Status: Not of concern
Herbaceous perennial from a branched, woody base, the flowering, leafy stems 2-6 dm. tall.
Basal leaves several, pinnate, the leaflets 9-17, oval, 1-2 cm. long, coarsely serrate; cauline leaves reduced but with leaf-like stipules.
Inflorescence of ovoid, dense spikes on long peduncles, 8-20 mm. long, each flower subtended by a papery, ovate bract and 2 lateral bractlets; flowers mostly imperfect, the lower ones staminate, the upper ones pistillate; calyx urn-shaped, greenish to rose-tinged, the 4 lobes broad, spreading and petal-like; petals none; stamens about 12, pistils 2.
Fruiting calyx 4-5 mm. long, woody and warty.