| Ageratina occidentalis | |
|---|---|
| Scientific classification | |
| Kingdom: | Plantae |
| (unranked): | Angiosperms |
| (unranked): | Eudicots |
| (unranked): | Asterids |
| Order: | Asterales |
| Family: | Asteraceae |
| Tribe: | Eupatorieae |
| Genus: | Ageratina |
| Species: | A. occidentalis |
| Binomial name | |
| Ageratina occidentalis (Hook.) King & H. Rob. |
|
| Synonyms | |
|
Eupatorium occidentale |
|
Ageratina occidentalis is a species of flowering plant in the daisy family 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. This is a rhizomatous perennial herb growing fuzzy green or purple stems to a maximum height near 70 centimeters. The glandular leaves are triangular in shape with serrated edges. The inflorescence is a dense cluster of fuzzy flower heads containing long, protruding disc florets in shades of white, pink, and blue. There are no ray florets. The fruit is an achene a few millimeters long with a rough, bristly pappus.