Clustered Thistle

Cirsium brevistylum

Clustered Thistle

Matt Lavin from Bozeman, Montana, USA

Taxonomy

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

Growth Characteristics

Life Cycle:
Annual | Biennial | Perennial
Growth Habit:
Forb/herb
Height:
8-12 ft
Light Requirements:
Full Sun
Drought Tolerance:
High
Bloom Months:
apr, may, jun, jul, aug, sep
Bloom Colors:
White, Pink, Purple

Native Range

United States: California, Idaho, Montana, Oregon, Washington, Canada: British Columbia

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: Fuzzy-horned bumble bee (Bombus mixtus), Fuzzy-horned bumble bee (Bombus mixtus), Yellow head bumble bee (Bombus flavifrons), Yellow head bumble bee (Bombus flavifrons)

Soil Requirements

Soil Type:
moist, well-drained loamy soil
pH:
5.5 - 7.0 (slightly acidic to neutral)
Drainage:
good drainage required
Moisture:
consistently moist
Notes:
prefers riparian zones and wet meadows

Germination Information

Pre-treatment: None required

Establishment: This plant prefers habitats that fall into the categories of either Coastal, Meadow, or West-Side Forest. It can be found in parts of Southeastern Canada as well as portions of Oregon, Washington and Northern California.

Source: npn.rngr.net