Field Thistle
Ohio Prairie Plant Species
Common Name: Field Thistle
Latin Name: Cirsium discolor [Pronounced: "SIRR-see-uhm DIS-cul-er"]
Type of Plant: Perennial Forb
Identification Helps: This tall thistle has a characteristic, usually single flower (see photo to the left) in July through September. The plant can be up to 6-ft tall. Leaves are as shown.
Preferred Growing Conditions in the Wild: Field thistle grows in both prairies and other non-prairie old-field habitats.
Preferred Soils: Field thistle grows on mesic to slightly hydric soils.
Seasons of Growth and Bloom: Blooms from July through October, but primarily in July and August.
Natural Distribution in Ohio: Found in all major Ohio prairies, and elsewhere in Ohio.
Description and General Information: Because this species grows in many non-prairie environments in Ohio, often in un-mowed old fields, many would regard this plant as a mere weed, not a real Ohio prairie plant. But this is one of a few native prairie plants that are able to invade and grow in disturbed or unmowed old fields outside of original prairie areas. Only a few prairie species can do this.