Native Plants

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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 Notes: Up to about 2 feet tall.
Fruit: Fruit is a cypsela (pl. cypselae). Though technically incorrect, the fruit is often referred to as an achene.

Bloom Information

Bloom Color: White , Red , Pink , Blue , Purple
Bloom Time: Jun , Jul , Aug , Sep , Oct

Distribution

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.

Propagation

Description: Propagate by division or seed.
Seed Treatment: Stratify.
Commercially Avail: yes

Web Reference

Webref 30 - Calflora (2018) Calflora
Webref 38 - Flora of North America (2019) Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
Webref 23 - Southwest Environmental Information Network (2009) SEINet - Arizona Chapter

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

Metadata

Record Modified: 2022-10-31
Research By: TWC Staff

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