Centaurea cyanusCentaurea cyanus (Cornflower, Bachelor's button, Basket flower, Bluebottle, Boutonniere flower, Hurtsickle) is a small annual flowering plant in the family Asteraceae, native to Europe. It is an annual plant growing to 40-90 cm tall, with grey-green branched stems. The leaves are lanceolate, 1-4 cm long. The flowers are most commonly an intense blue colour, produced in flowerheads (capitula) 1.5-3 cm diameter, with a ring of a few large, spreading ray florets surrounding a central cluster of disc florets. The blue pigment is protocyanin, which in roses is red.