Thistle, Canada

Canada thistle is a perennial broadleaf plant that inhabits stream banks, forest openings, rangelands, hillsides, gardens, crop fields, roadsides, and other open disturbed sites. The plant stands erect to 3-4 feet and grows in clumps or patches. Its stems are slender and hairless or nearly hairless. Leaves are oblong to spear-shaped, mostly 2-8 inches long and prickly. Leaf edges range from nearly smooth to shallow-lobed and toothed. Flowers bloom from June through October. The flower head is cylindrical or narrowly egg- to bell-shaped. Narrow, white, purple, or pink flowers cluster above. Canada thistle reproduces by seed and from cut roots.