Centaurea cyanus (family Asteraceae) seeds. Also known as 'Bachelor Buttons' and 'Bluebonnet', Cornflower is native to Europe and is found growing wild in grain ("corn") fields, hence the name. (fields growing grains such as wheat, barley, rye, or oats were formerly known as "corn fields" in England). It is now endangered in its native habitat by agricultural intensification, particularly over-use of herbicides, destroying its habitat; in the United Kingdom it has declined from 264 sites to just 3 sites in the last 50 years.