Identifying features include: Like other thistles, bull thistle is armed with a great number of spines that can and will penetrate exposed skin. For more information visit the Midwest Invasive Species ...

Californian thistle is one of the most common thistle species in New Zealand. It is very troublesome in pastures because it is so difficult to control. Once a plant is established in pasture, it forms ...

Scotch thistle is the most common thistle species in New Zealand with spines on both the leaf surface and margins. Scotch thistle is a biennial weed, so it depends quite heavily on the establishment ...

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 ...