Thistle

thisl, a common name given to a large group of plants of the composite family. They are allied closely to the burdock. They are characterized by spiny leaves and bracts. The bracts of the head form an acorn-like cup. The flowers are usually purple and some are of great beauty. Growing as they often do in standing grain, the thistles are very troublesome weeds. The worst is the Canadian thistle. The more it is plowed up and persecuted, the more it seems to spread. The only way to exterminate it is to get it entirely out of the ground, for each fragment left behind produces a new plant. The thistle is the national flower of Scotland. Authors are disagreed, however, as to which of several species is to be regarded as the national emblem. See Seeds; Goldfinch; Dumbarton