Centaurea cyanus, commonly known as cornflower, bachelor's button, bluebottle, boutonniere flower, hurtsickle or cyani flower, is an annual flowering plant in the family Asteraceae and is native to Europe. It grows to 16-35 inches tall, with grey-green branched stems. The leaves are lanceolate, 1–4 cm long. The flowers are most commonly an intense blue colour, produced inflowerheads (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.