Eaton's Thistle

Cirsium eatonii

Taxonomy

Division:
Magnoliophyta | - Flowering plants
Family:
Asteraceae
Genus:
Cirsium
Species:
Cirsium eatonii

Growth Characteristics

Life Cycle:
Biennial | Perennial
Growth Habit:
Forb/herb
Height:
4-6 ft
Light Requirements:
Full Sun
Drought Tolerance:
Medium
Bloom Months:
jun, jul, aug, sep
Bloom Colors:
White, Pink, Yellow, Purple

Native Range

United States: Colorado, Idaho, Montana, Nevada, Utah, Wyoming

Keystone Species Ranking

Bee Keystone:
★★☆☆☆ Based on number of native bee species using this genus for pollen and nectar (Source: National Wildlife Federation)

Reported Fauna Sightings

Bees: Black-tailed bumble bee (Bombus melanopygus), Black-tailed bumble bee (Bombus melanopygus), Central bumble bee (Bombus centralis), Central bumble bee (Bombus centralis), Frigid Bumble Bee (Bombus frigidus), Frigid Bumble Bee (Bombus frigidus), Fuzzy-horned bumble bee (Bombus mixtus), Fuzzy-horned bumble bee (Bombus mixtus), High country bumble bee (Bombus kirbiellus), High country bumble bee (Bombus kirbiellus), Two-form bumble bee (Bombus bifarius), Two-form bumble bee (Bombus bifarius), Yellow head bumble bee (Bombus flavifrons), Yellow head bumble bee (Bombus flavifrons)

Soil Requirements

Soil Type:
well-drained, rocky or sandy soil
pH:
6.0 - 7.5 (slightly acidic to neutral)
Drainage:
excellent drainage required
Moisture:
dry to moderate
Notes:
often found in mountainous regions

Germination Information

Pre-treatment: Cold-moist stratification for 30 days at 1–5°C (34–41°F).

Source: OpenAI GPT-4o