Family: Asteraceae, Aster view all from this family

Description Solitary or clustered firm stems bear flat-topped clusters of small fuzzy white flower heads composed entirely of disk flowers.
Flowers: heads about 1/5" (5 mm) long and 1/6" (4 mm) wide.
Leaves: 2 1/2-7" (6-18 cm) long, opposite, ovate, stalked, coarsely or sometimes sharply toothed.
Fruit: tiny, seed-like, bearing white bristles.
Height: 1-3' (30-90 cm).

Warning White Snakeroot is poisonous to livestock. The toxins will pass into milk produced by animals that ingest the plant, and the tainted milk can fatally poison humans.

Flower July-October.

Habitat Woods and thickets.

Range S. Ontario to New Brunswick; south through New England to Virginia and upland Georgia; west to Louisiana and ne. Texas; north to Wisconsin.

Discussion This plant used to be placed in the genus Eupatorium, as did Smaller White Snakeroot (A. aromatica), a nonaromatic plant despite its name; it has less coarsely toothed leaves, the upper ones stalkless. Other similar species are Late-flowering Thoroughwort (Eupatorium serotinum), which has long-stalked lanceolate leaves with 3-5 main veins, and Hyssop-leaf Thoroughwort (E. hyssopifolium), with very narrow leaves in whorls of 3-4.