White Boneset,  Eupatorium album
Asteraceae or Sunflower Family
 

Flowers tiny, a few each in small heads, together forming a large flattish cluster at the top of the plant.  1-3 feet tall.  Leaves long, pointed, sharply toothed,  opposite each other.  At the base of each leaf there is a cluster of small leaves, as at lower left.  Blooms in the fall.

Dry woods.  Relatively uncommon in the Park.

Members of the genus Eupatorium with white flowers are called bonesets or snakeroots.  Boneset (E. perfoliatum) has lower leaves that connect across the stalk and likes more open, moist areas. White snakeroot (Ageratina altissima) has wider leaves with long stalks. Upland boneset (E. sessilifolium) has narrow leaves with no stalks. Sweet-scented Joe-Pye weed (E. purpureum) has pale pink flowers and leaves in whorls.