Canada thistle (Creeping thistle, California thistle, Cursed thistle) is a shiny green, spiny thistle native to Europe, Western Asia, and Northern Africa.

It’s likely one of the first invasive species introduced to North America and received its name by early settlers blaming its emergence on French traders from Canada.

Plants form thick infestations through creeping rhizomatous roots that crowd out forage grasses in pastures and rangelands, reducing crop yields and production.

Canada thistle is commonly found growing on roadsides, cultivated fields, pastures, logged forests, riverbanks, and other disturbed areas where it also out-grows native species. It’s even considered an injurious weed species within its native range.

East Kootenay Invasive Species Council photo

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