Ageratina occidentalis (Hook.) R.M. King & H. Rob.

Ageratina occidentalis (Hook.) R.M. King & H. Rob.. Ageratina occidentalis is a species of flowering plant in the family Asteraceae known by the common name western snakeroot or western eupatorium. It is native to the western United States where it grows in several types of habitat. It is found in California, Oregon, Washington, Idaho, Montana, Nevada, and Utah.