Centaurea cyanus ('Cornflower, Bachelors button, Bluebottle, Boutonniere flower, Hurtsickle, Cyani flower) is a small annual flowering plant in the family Asteraceae, native to Europe.
Preparative RP-HPLC analysis of a methanol extract of the seeds of Centaureacyanus afforded four indole alkaloids: moschamine, cis-moschamine, centcyamine and cis-centcyamine, the latter two being natural products. Structures of these compounds were elucidated by comprehensive spectroscopic analyses. General toxicity of the isolates was determined by Brine Shrimp Lethality bioassay.

 It is an annual plant growing 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 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.