Murdock's Thistle

Cirsium tweedyi

Native to:
United States

📍 View on iNaturalist →

Taxonomy

Division:
Magnoliophyta | - Flowering plants
Family:
Asteraceae
Genus:
Cirsium
Species:
Cirsium tweedyi
USDA Symbol:
CIMU2

Growth Characteristics

Life Cycle:
Biennial | Perennial
Growth Habit:
Forb/herb
Height:
120 cm
Light Requirements:
Full Sun
Drought Tolerance:
Medium
Bloom Months:
jun,jul,aug
Bloom Colors:
white, pink, lavender

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)

Garden & Ecology Notes

Wildlife Value:
bees, butterflies, birds
Deer Resistant:
Yes
Fire Ecology:
Fire adapted — tolerates or benefits from fire
Fire Notes:
Resprouts from rootstock following fire; often increases in abundance in early post-fire years.

Soil Requirements

Soil Type:
well-drained, sandy or rocky soil
pH:
6.0 - 7.5 (slightly acidic to neutral)
Drainage:
excellent drainage required
Moisture:
dry to moderate
Notes:
native to open, rocky slopes and meadows

Propagation & Germination

Stratification:
Cold/moist stratification required — 30–60 days
Germination Time:
14–30 days
Notes:
Seeds germinate best with light exposure and cool temperatures after cold stratification.

The above propagation data sourced from Claude AI