For more information visit Midwest Invasive Species Information Network (MISIN). European marsh thistle can colonize areas quite aggressively and can be difficult to remove from areas due to the wet ...

For more information visit Midwest Invasive Species Information Network (MISIN). Canada thistle forms extremely extensive root systems that need to be repeatedly damaged to keep them from growing back ...

Native thistles are integral to the local ecosystem; some, like the Sacramento Mountain thistle (Cirsium vinaceum), for example, are threatened species. You don't want to remove them by accident.

Easily recognizable due to its vase-shaped purple flowers with dandelion-like seeds, Canada thistle (Cirsium arvense) is a particularly aggressive invasive plant. Despite its name, Canada thistle ...