Canada Thistle
Canada Thistle, a European weed, introduced into Canada and the United States. It has spiky purplish-pink flowers. The stem is smooth and the leaves are spiny. Its creeping rhizomes form extensive mats. Nothing else grows in a Canada thistle patch, and the plant tends to persist despite efforts to eliminate it.
Canada thistle is Cirsium arvense of the family Compositae.
Canada thistle is a weed with prickly leaves and pink-purple or white flowers.