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 ...

Canada thistle forms extremely extensive root systems that need to be repeatedly damaged to keep them from growing back. These root systems can spread very aggressively and can expand from 6 feet wide ...

Should you get rid of Canada thistle? Find out what the experts say. Lots of invasive plants hurt the environment, but giant hogweed hurts people, too. Its leaves grow up to 5 feet across ...

European marsh thistle, a terrestrial and wetland herbaceous biennial in the Asteraceae family, is an invasive plant that prefers moist soils ... European marsh thistle is distinguished from Canada ...