Canada thistle
noun
an Old World plant, Cirsium arvense, having small purple or white flower heads, now a troublesome weed in North America.
Origin of Canada thistle
An Americanism dating back to 1790–1800
Dictionary.com Unabridged
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for canada thistle
Little bits of Canada-thistle root half an inch long may send forth buds, and each bud grow to be an independent plant.
Seed Dispersal|William J. Beal
British Dictionary definitions for canada thistle
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012