Taxonomy

Division:

Magnoliophyta | - Flowering plants

Family:

Asteraceae

Genus:

Cirsium

Species:

Cirsium douglasii

USDA Symbol:

CIDO2

Growth Characteristics

Life Cycle:

Biennial | Perennial

Growth Habit:

Forb/herb

Height:

150 cm

Light Requirements:

Full Sun

Drought Tolerance:

Medium

Bloom Months:

may,jun,jul,aug

Bloom Colors:

white, pink, purple

Wildlife Benefits

Bees:

★☆☆☆☆ Documented bee visitation (GBIF)

Butterflies & Moths:

★☆☆☆☆ Documented Lepidoptera association (GBIF)

Caterpillars:

★☆☆☆☆ Recorded caterpillar host plant (HOSTS Database)

Keystone Species Ranking

Pollen Specialist Bee Keystone:

★★★★☆ Native pollen specialist bee species supported by this genus (NWF)

Host Plant for Caterpillars

Reported Fauna Sightings

Garden & Ecology Notes

Wildlife Value:

bees, butterflies, birds

Deer Resistant:

Yes

Fire Ecology:

Fire adapted — tolerates or benefits from fire

Fire Notes:

Resprouts from root crown following fire. Native thistles are often early colonizers of burned areas.

Soil Requirements

Soil Type:

moist, rich, well-drained loamy soil

pH:

5.5 - 7.5 (slightly acidic to neutral)

Drainage:

tolerates poor drainage

Moisture:

consistently moist

Notes:

commonly found in wetlands and marshy areas

Propagation & Germination

Stratification:

Cold/moist stratification required — 30–90 days

Germination Time:

14–42 days

Notes:

Light may enhance germination. Seeds germinate best with cool temperatures after cold stratification.

The above propagation data sourced from Claude AI