Centaurea cyanus
Also known as bachelor's button, bluebonnet, bluebottle, blue centaury and cyani. This is an annual herb
which is native to Europe and cultivated in North America. It has a stiff,
branched stem which grows to 12 to 24 inches high. The leaves are narrow and
lobed near the base. Flowers appear on the plant between June and August,
and are blue in colour. (Some varieties occasionally produce white or
rose-coloured flowers).
Cornflowers are diuretic and tonic, and are
used for dyspepsia. In mixed teas, the herb can be used for cosmetic
purposes. The flowers may also be made into an eyewash or eyedrops, or into
a compress for the eyes.