CORNFLOWER (Centaurea Cyanus), a well-known plant of the family Compositae, called also bluebottle and bachelor's button. It is a native of Europe, a familiar cornfield weed in Great Britain, and has become widely naturalized from cultiva tion in many parts of North America from Quebec to the Pacific coast, where in Washington and California it is a common way side weed. It is a slender, branching annual, 1 ft. to 2 f t. high, with narrow, more or less toothed or divided leaves and brilliant blue or sometimes purple or white flowers, in heads an inch or more across, borne on long leafless stalks. In the United States it is very popular for garden planting, being one of the "old fashioned flowers." (See CENTAUREA.)