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Search for native plants by scientific name, common name or family. If you are not sure what you are looking for, try the Combination Search or our Recommended Species lists.

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Ageratina occidentalis (Western snakeroot)
Bransford, W.D. and Dolphia

Ageratina occidentalis

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

Western Snakeroot, Western Thoroughwort

Asteraceae (Aster Family)

Synonym(s): Eupatorium occidentale

USDA Symbol: AGOC2

USDA Native Status: L48 (N)

This low subshrub, which rarely grows taller than 2 ft., is covered with short, broad, pointed, bright green aromatic leaves topped by masses of red-purple flower heads.


From the Image Gallery

1 photo(s) available in the Image Gallery

Plant Characteristics

Duration: Perennial
Habit: Herb
Size Class: 1-3 ft.

Bloom Information

Bloom Color: Red , Purple
Bloom Time: Jul , Aug , Sep


USA: CA , ID , MT , NV , OR , UT , WA
Native Distribution: N. CA to c. WA, extreme w. MT & UT
Native Habitat: Open, rocky places; 6500-11,000 ft.

Growing Conditions

Light Requirement: Sun
Soil Description: Granitic rocks.
Conditions Comments: Not Available


Description: Propagate by division or seed.
Seed Collection: Not Available
Seed Treatment: Stratify.
Commercially Avail: yes

Additional resources

USDA: Find Ageratina occidentalis in USDA Plants
FNA: Find Ageratina occidentalis in the Flora of North America (if available)
Google: Search Google for Ageratina occidentalis


Record Modified: 2007-01-01
Research By: TWC Staff

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