Clustered Thistle
Cirsium brevistylum
- Native to:
- Canada, United States
iNaturalist: © stewartwechsler (iNaturalist #55550214)
Taxonomy
- Division:
- Magnoliophyta | - Flowering plants
- Family:
- Asteraceae
- Genus:
- Cirsium
- Species:
- Cirsium brevistylum
- USDA Symbol:
- CIBR2
Growth Characteristics
- Life Cycle:
- Annual | Biennial | Perennial
- Growth Habit:
- Forb/herb
- Height:
- 200 cm
- Light Requirements:
- Full Sun
- Drought Tolerance:
- Low
- Bloom Months:
- jun,jul,aug,sep
- Bloom Colors:
- pink, purple, white
Wildlife Benefits
- Bees:
- ★☆☆☆☆ Documented bee visitation (GBIF)
- Butterflies & Moths:
- ★☆☆☆☆ Documented Lepidoptera association (GBIF)
Keystone Species Ranking
- Pollen Specialist Bee Keystone:
- ★★★★☆ Native pollen specialist bee species supported by this genus (NWF)
Reported Fauna Sightings
Bees: Fuzzy-horned bumble (Bombus mixtus)
Garden & Ecology Notes
- Wildlife Value:
- bees, butterflies, birds, hummingbirds
- Deer Resistant:
- Yes
- Fire Ecology:
- Fire adapted — tolerates or benefits from fire
- Fire Notes:
- Resprouts from root crown following fire; often increases in abundance post-burn in meadow and open forest habitats.
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
Propagation & Germination
- Stratification:
- Cold/moist stratification required — 30–60 days
- Germination Time:
- 14–30 days
- Notes:
- Seeds germinate readily after cold stratification. Light may enhance germination.
The above propagation data sourced from Claude AI
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