cornflowers (Centaurea cyanus). An annual flowering plant in the family Asteraceae native to Europe.commonly known as cornflower or bachelor's button. In the past it often grew as a weed in cornfields (in the broad sense of "corn", referring to grains, such as wheat, barley, rye, or oats), hence its name. Intensive cultivation has reduced it to a UK rarity but in mountian areas through Eruoep it still thrives with other cornfield weeds. Preci, Sibillini, Umbria. Italy May 2018