This native thistle is a perennial herb growing erect to a maximum height approaching one meter.

This native thistle is biennial to perennial, producing an erect, leafy stem which can reach two meters in height.

In North America, there are also Trichosirocalus control programs, but they have proved detrimental to native thistles.

Subsequent research determined that the weevil reduced seed production of the native thistle.

This native thistle is an annual or biennial herb known to reach three meters in height.

This native thistle is a biennial or perennial herb with a maximum height just over a meter.

This native thistle is a perennial herb growing up to about 1.5 meters tall.

This native thistle grows in wet boggy habitats.

This native thistle is annual or biennial, reaching two meters in height and known to exceed three meters at times.

He lamented that Scotland seemed to be taking over England: "like their native thistles, they never can be weeded out".