| canada | ontario | carduus acanthoides | species | 4 | 0 |
| canada | ontario | carduus nutans | species | 6 | 0 |
| canada | ontario | carduus nutans subsp. nutans | subspecies | 2 | 0 |
| canada | saskatchewan | carduus nutans | species | 2 | 0 |
| czech republic | | carduus nutans | species | 1 | 0 |
| czech republic | south moravian region | carduus acanthoides | species | 1 | 0 |
| finland | | carduus crispus | species | 1 | 0 |
| france | | carduus defloratus | species | 1 | 0 |
| germany | | carduus acanthoides | species | 10 | 0 |
| germany | | carduus crispus | species | 12 | 0 |
| germany | | carduus nutans | species | 2 | 0 |
| italy | lombardy region | carduus defloratus | species | 2 | 0 |
| italy | sardinia autonomous region | carduus argyroa | species | 1 | 0 |
| italy | sardinia autonomous region | carduus cephalanthus | species | 1 | 0 |
| italy | sardinia autonomous region | carduus macrocephalus | species | 1 | 0 |
| italy | sardinia autonomous region | carduus pycnocephalus | species | 1 | 0 |
| kuwait | | carduus pycnocephalus | species | 6 | 0 |
| portugal | | carduus tenuiflorus | species | 2 | 0 |
| romania | | carduus personata subsp. albidus | subspecies | 2 | 0 |
| south africa | | carduus keniensis | species | 5 | 0 |
| south africa | | carduus nyassanus | species | 5 | 0 |
| south korea | | carduus crispus | species | 2 | 0 |
| spain | | carduus carlinoides | species | 2 | 0 |
| spain | | carduus defloratus | species | 2 | 0 |
| united kingdom | | carduus crispus | species | 3 | 0 |
| united kingdom | | carduus nutans | species | 4 | 0 |
| united kingdom | | carduus tenuiflorus | species | 3 | 0 |
| united states | | carduus acanthoides | species | 2 | 0 |
| united states | | carduus nutans | species | 86 | 0 |
| united states | | carduus pycnocephalus | species | 1 | 0 |
| united states | | carduus tenuiflorus | species | 2 | 0 |
| united states | new york | carduus sp. vanneste 466 | species | 4 | 0 |
| united states | north dakota | carduus nutans | species | 2 | 0 |