Ageratina altissima (L.) R.M. King & H. Rob.

Ageratina altissima (L.) R.M. King & H. Rob.. Ageratina altissima, also known as white snakeroot, richweed, or white sanicle, is a poisonous perennial herb in the family Asteraceae, native to eastern and central North America. An older binomial name for this species is Eupatorium rugosum, but the genus Eupatorium has undergone taxonomic revision by botanists, and some species once included in it have been moved to other genera.