| Ageratina occidentalis | |
|---|---|
| | |
| Regional Parks Botanic Garden Berkeley, California | |
| Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Asterids |
| Order: | Asterales |
| Family: | Asteraceae |
| Genus: | Ageratina |
| Species: | A. occidentalis |
| Binomial name | |
| Ageratina occidentalis | |
| Synonyms [2] | |
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Ageratina occidentalis is a species of flowering plant in the family Asteraceae known by the common name western snakeroot or western eupatorium. [3] 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. [4]
Ageratina occidentalis is a rhizomatous perennial herb growing fuzzy green or purple stems to a maximum height near 70 centimeters. Its leaves are glandular and triangular, 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. [5]
Ageratina is derived from Greek meaning 'un-aging', in reference to the flowers keeping their color for a long time. This name was used by Dioscorides for a number of different plants. [6]
The name Eupatorium comes from the Greek king Mithridates VI Eupator, who is said to have discovered that a species in the genus could be used as an antidote to a common poison. [7]