Ageratina altissima (L.) King & H.E. Robins.
Asteraceae (Aster Family)
or clustered firm stems bear flat-topped clusters of small fuzzy white flower heads composed entirely of disk flowers.
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.
Image Gallery: 1 photo(s) available
Plant CharacteristicsDuration: Perennial Habit: Herb Flower:
Fruit: Size Class:
Bloom InformationBloom Time: Jul , Aug , Sep , Oct
AL , AR , CT , DE , FL , GA , IL , IN , IA , KS , KY , LA , ME , MD , MA , MI , MN , MS , MO , NE , NH , NJ , NY , NC , ND , OH , OK , PA , RI , SC , SD , TN , TX , VT , VA , WV , WI , DC Canada: NB
, SK Native Distribution:
S. Ontario to New Brunswick; south through New England to Virginia and upland Georgia; west to Louisiana and ne. Texas; north to Wisconsin. Native Habitat:
Woods and thickets. USDA Native Status: L48(N), CAN(N)
Growing ConditionsWater Use: Low
Light Requirement: Sun , Part Shade
Soil Moisture: Moist , Dry
Drought Tolerance: High
Conditions Comments: Prefers full sun but will tolerate shade in more southern locations.