The Canada Thistle has been severely condemned by farmers in this country because of its rapid spread and the extreme difficulty with which its creeping roots are eradicated from the soil. It grows in extensive colonies, and quickly monopolizes our fertile meadows and pasture lands. The slender, leafy stalk is grooved and branching at the top, and grows from one to three feet high, from a perennial creeping rootstalk. The long, lance-shaped leaf is deeply cut into very prickly lobed or coarsely toothed segments, which bristle with many prickers, as they become curled or ruffled. The colour is grayish green, and the midrib is whitish. They slightly clasp the stalk, and the lower ones are stemmed. The numerous small, purple or whitish flower heads are loosely clustered on the tips of the branches. Many tubular florets with prominent purple stamens and white pistils compose the head. The latter is set in an egg-shaped, grayish green cup, which is covered with short, weak prickers. The flowers are fragrant and pleasing, but after they mature they become anything but sightly. This species is very common in cultivated fields and pastures and along roadsides from Newfoundland to Virginia, Minnesota and Nebraska, from July to September.