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 ...

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 ...

Today the plant is found in all states except Alaska and Florida. While the Russian thistle's rampant spread through North America is perhaps the more well-recorded invasion, this species has also ...

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 ...

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 ...

This thistle was placed on the endangered species list in 1987 due to severe threats from cattle grazing in its habitat on the Lincoln National Forest, home to 95 percent of its populations. After the ...

This thistle was placed on the endangered species list in 1987 due to severe threats from cattle grazing in its habitat on the Lincoln National Forest, home to 95 percent of its populations. After the ...