Canada thistle
noun
: a European thistle (Cirsium arvense) with pinkish-purple or white flowers naturalized as a weed in North America
Examples of Canada thistle in a Sentence
Recent Examples on the Web
Canada thistle is a tall perennial plant that is highly invasive and will spread aggressively.
—
Andy Wilcox, Better Homes & Gardens, 27 Aug. 2025
Several other weeds fall under this law, including Canada thistle, Russian thistle, redroot pigweed, common ragweed and others.
—Ashlyn Messier, Fox News, 19 Dec. 2024
The other noxious weeds listed in both states are Canada thistle and Kudzu.
—Natalie Wallington, Kansas City Star, 9 May 2024
Unlike many other perennial weeds, dandelions don’t spread vegetatively, that is, by creeping along the ground like blackberry vines, or spreading underground by the root like Canada thistle.
—oregonlive, 19 Apr. 2022
In addition, the State of Wisconsin also defined three plants to be noxious weeds in the 1970s, including Canada thistle, leafy spurge and field bindweed.
—Jennifer Rude Klett, Milwaukee Journal Sentinel, 16 Sep. 2021
Also prevalent are Callery pear, better known as the Bradford pear, wintercreeper, Canada thistle, garlic mustard, burning bush, multiflora rose, autumn olive, Japanese honeysuckle and Japanese knotweed.
—John Tuohy, The Indianapolis Star, 9 Nov. 2020
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Andy Wilcox, Better Homes & Gardens, 27 Aug. 2025
Several other weeds fall under this law, including Canada thistle, Russian thistle, redroot pigweed, common ragweed and others.
—Ashlyn Messier, Fox News, 19 Dec. 2024
The other noxious weeds listed in both states are Canada thistle and Kudzu.
—Natalie Wallington, Kansas City Star, 9 May 2024
Unlike many other perennial weeds, dandelions don’t spread vegetatively, that is, by creeping along the ground like blackberry vines, or spreading underground by the root like Canada thistle.
—oregonlive, 19 Apr. 2022
In addition, the State of Wisconsin also defined three plants to be noxious weeds in the 1970s, including Canada thistle, leafy spurge and field bindweed.
—Jennifer Rude Klett, Milwaukee Journal Sentinel, 16 Sep. 2021
Also prevalent are Callery pear, better known as the Bradford pear, wintercreeper, Canada thistle, garlic mustard, burning bush, multiflora rose, autumn olive, Japanese honeysuckle and Japanese knotweed.
—John Tuohy, The Indianapolis Star, 9 Nov. 2020
Cite this Entry
“Canada thistle.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/Canada%20thistle. Accessed 30 Oct. 2025.
Copy CitationLove words? Need even more definitions?
Merriam-Webster unabridged
Share