Also known as bachelor's-button, bluebottle, and hurtsickle, cornflower is a member of the daisy family (Asteraceae) and is an old favourite that has many varieties and colours, which makes it an attractive garden plant. As for medicinal qualities it's the familiar bright blue cornflower, Centaurea cyanus (commonly known as blue bachelor's button), that's used. According to folklore, the herb improves eyesight and a decoction of the dried flowers was used to treat eye inflammations.The leaves were juiced and applied to wounds and steeped in wine to treat fevers of pestilent diseases. Research indicates that cornflowers may have some effect as an astringent (an agent that contracts biological tissue and therefore stops bleeding) because of its tannin content but there's little evidence to support its effect in treating fevers.
Cornflower's Latin name is derived from a mythical centaur that was worshipped as the father of medicine by the Ancient Greeks and one of its common names, hurtsickle, comes from English farmers who considered it a weed and blunted their sickles when cutting the tough stem.
Native to the Mediterranean, cornflower is completely naturalized in England and widely cultivated in Australia although it does escape from gardens at times. It can be found growing wild in waste ground, roadsides and fields.
The herb is an annual that is easily cultivated and has a wiry, erect downy stem that grows to a height of 30 to 60 centimetres. Brilliant blue solitary thistle-like flower heads appear at the ends of branches from spring to summer and the greyish-green long alternate, lance-shaped leaves are downy like the stem.
Cornflowers are popularly used in dried flower arrangements because they retain their beautiful colour when dried. A blue ink can be made by mixing the juice from the flower with alum water but the colour doesn't work well as a cloth dye.
Whatever its uses the herb has a place in the English language because its name has been taken to describe incredibly blue eyes - cornflower blue.