White Thistle

Cirsium hookerianum

White Thistle

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Taxonomy

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

Growth Characteristics

Life Cycle:
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

Native Range

United States: Idaho, Montana, Washington, Wyoming, Canada: Alberta, 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: Brown-belted bumble bee (Bombus griseocollis), Brown-belted bumble bee (Bombus griseocollis), Hunt's bumble bee (Bombus huntii), Hunt's bumble bee (Bombus huntii), Morrison bumble bee (Bombus morrisoni), Morrison bumble bee (Bombus morrisoni), Nevada bumble bee (Bombus nevadensis), Nevada bumble bee (Bombus nevadensis), Two-form bumble bee (Bombus bifarius), Two-form bumble bee (Bombus bifarius), White-shouldered bumble bee (Bombus appositus), White-shouldered bumble bee (Bombus appositus), Yellow bumble bee (Bombus fervidus), Yellow bumble bee (Bombus fervidus), 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 open, grassy areas in native range

Germination Information

Pre-treatment: 5 month outdoor cold, moist stratification

Establishment: Collect mature achenes in mid September when they turn grey and are easily separated from the receptacle. Seeds are collected in paper bags and kept in a well ventilated drying shed prior to cleaning.

Source: npn.rngr.net