Mountain Thistle

Cirsium scopulorum

Taxonomy

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

Growth Characteristics

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

Native Range

United States: Colorado, New Mexico, 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: Frigid Bumble Bee (Bombus frigidus), Frigid Bumble Bee (Bombus frigidus), Western bumble bee (Bombus occidentalis), Western bumble bee (Bombus occidentalis), Yellow head bumble bee (Bombus flavifrons), Yellow head bumble bee (Bombus flavifrons)

Soil Requirements

Soil Type:
rocky, well-drained, nutrient-poor soil
pH:
6.0 - 7.5 (slightly acidic to neutral)
Drainage:
excellent drainage required
Moisture:
dry to moderate
Notes:
native to mountainous regions with sparse vegetation

Germination Information

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

Source: OpenAI GPT-4o