Fauna
Plant

Bull Thistle

Cirsium vulgare

Also known as Spear Thistle, Common Thistle, Fuller's Thistle, Scots Thistle

Bull thistle forms a robust biennial rosette in its first year, sending up a tall, spiny, winged stem capped with dense magenta flower heads in its second summer. Each dark green leaf features deeply lobed margins ending in sharp, stiff yellow spines that deter most grazing herbivores. Downy white seed heads release thousands of windborne achenes each autumn, allowing this adaptable species to rapidly colonize disturbed soils.

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Bull Thistle reference1 / 7
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Least ConcernConservation statusIUCN Red List categoriesLCNTVUENCREWEXLeast ConcernRed List categories, explained →
Key facts
Diet & preyAutotrophic (Photosynthesis)
Predators
  • Goldfinches
  • Painted Lady Caterpillars
  • Mammalian Browsers
ThreatsBiological control agents, land management, mechanical removal
HabitatsPastures, roadsides, disturbed ground, grasslands, cleared woodlands
Life span2 years (Biennial)
Classification
  1. OrderAsterales
  2. FamilyAsteraceae
  3. GenusCirsium
  4. SpeciesCirsium vulgare
Range & activity
Range data is not available yet.
Safe observation
Interaction riskLow
  1. Low
  2. Moderate
  3. High
  4. Very high
Why interaction risk is low
Rigid spines on leaves and stems can puncture skin; wear heavy gloves when handling.
Why it is dangerous
Sharp, stiff spines lining the stems, leaves, and floral bracts easily puncture skin and thin clothing, causing mechanical irritation.
How to recognize a risky encounter
Identified by winged spiny stems and lance-shaped leaf lobes terminating in hard yellow prickles.
What to do
Wear thick leather gloves and long sleeves when clearing plants, and avoid walking bare-legged through dense stands.
Responsible observation
  • Identification: Look for deeply lobed, spine-tipped leaves with prickly wings running up the stem.
  • Management: Dig young rosettes below the root crown before flower heads set seed.
  • Wildlife Observation: Watch purple flower heads in midsummer to spot visiting bumblebees and butterflies.
Related species
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