Centaurea cyanus: seeds

Centaurea cyanus, known in English as bachelor's buttons or cornflower, and in French as centauré or bluet, is an annual with flowers in blue, white, pink, or red, native to Europe.

This is my first year growing centaurea. Since the seeds were cheap, I am experimenting with winter-sowing this hardy annual. The seeds are light brown, about 3 long, and easy to handle.