Tall Thistle
Cirsium altissimum
- Native to:
- United States
iNaturalist: © calmac24 (iNaturalist #311105239)
Taxonomy
- Division:
- Magnoliophyta | - Flowering plants
- Family:
- Asteraceae
- Genus:
- Cirsium
- Species:
- Cirsium altissimum
- USDA Symbol:
- CIAL2
Growth Characteristics
- Life Cycle:
- Biennial
- Growth Habit:
- Forb/herb
- Height:
- 300 cm
- Light Requirements:
- Full Sun,Part Shade
- Drought Tolerance:
- Medium
- Bloom Months:
- jul,aug,sep,oct
- Bloom Colors:
- pink, purple, lavender
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
⚠️Swamp Metalmark (Calephelis mutica)
Reported Fauna Sightings
Bees: Black and gold bumble bee (Bombus auricomus), eastern thistle longhorn bee (Melissodes desponsus), Half-black bumble bee (Bombus vagans), Southern plains bumble bee (Bombus fraternus), Two-spotted bumble bee (Bombus bimaculatus) Moths:Snowberry Clearwing (Hemaris diffinis) Butterflies:Atalopedes Scudder, Black Swallowtail (Papilio polyxenes), Calephelis muticum, Cloudless Sulphur (Phoebis sennae), Eastern Tiger Swallowtail (Papilio glaucus), Great Spangled (Argynnis cybele), Julia butterfly (Dione vanillae), ⚠️Monarch butterfly (Danaus plexippus), Painted Lady (Vanessa cardui), Pipevine Swallowtail (Battus philenor), Silver-spotted Skipper (Epargyreus clarus), Sleepy Orange (Eurema nicippe), Spicebush Swallowtail (Papilio troilus), Zabulon Skipper (Lon zabulon)
Garden & Ecology Notes
- Wildlife Value:
- bees, butterflies, goldfinches, native bees
- Deer Resistant:
- Yes
- Fire Ecology:
- Fire adapted — tolerates or benefits from fire
- Fire Notes:
- Resprouts from root crown following fire; found in fire-maintained prairie and savanna habitats.
Soil Requirements
- Soil Type:
- rich, well-drained loamy soil
- pH:
- 5.5 - 7.5 (slightly acidic to neutral)
- Drainage:
- good drainage preferred
- Moisture:
- dry to moderate
- Notes:
- thrives in open fields and prairies
Propagation & Germination
- Stratification:
- Cold/moist stratification required — 30–60 days
- Germination Time:
- 14–30 days
- Notes:
- Seeds germinate readily after cold stratification; light may improve germination rates.
The above propagation data sourced from Claude AI
Pre-treatment: Cold-moist stratification for 30 days at 1–5°C (34–41°F).
Source: Claude AI