Prairie Thistle (Cirsium discolor)

Beautiful purple flowers stand out in the summer prairie, attracting pollinators when in flower and birds for the seed. This thistle gets a bad wrap because it looks similar to some of the non-native invasive thistles, however this native species is a biennial or short-lived perennial and only spreads by seed... it is not considered aggressive at all and is an important plant of many Illinois prairies.


  • Acronym: CIRDIS
  • Life-Cycle: Biennial or Short-Lived Perennial
  • Bloom Color: Purple
  • Bloom Time: August - October
  • Typical Height: 72"
  • Light Preference: Full Sun
  • Soil Preference: Mesic
  • Root Structure: Taproot
  • Stratification: None Required
  • Seeds per Ounce: 6,200*
  • Seeds per Packet: 50*


Other scientific names used for this species:

  • None


Other common names used for this species:

  • Pasture Thistle


*Approximate, actual number of seeds may vary slightly by seed lot.

Cirsium discolor - Per Ounce