Centaurea cyanus


Centaurea cyanus, commonly known as cornflower or bachelor's button, is an annual flowering plant in the family Asteraceae, native to Europe. In the past it often grew as a weed in cornfields, hence its name. It is now endangered in its native habitat by agricultural intensification, particularly over-use of herbicides, destroying its habitat. It is also, however, through introduction as an ornamental plant in gardens and a seed contaminant in crop seeds, now naturalised in many other parts of the world, including North America and parts of Australia.

Description

Cornflower is an annual plant growing to 40–90 cm 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 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. It flowers all summer.

Distribution

Centaurea cyanus is native to temperate Europe, but is widely naturalized outside its native range. It has been present in the British Isles as an archaeophyte since the Iron Age. In the United Kingdom it has declined from 264 sites to just 3 sites in the last 50 years. In reaction to this, the conservation charity Plantlife named it as one of 101 species it would actively work to bring 'back from the brink'. In Co. Clare, Ireland, Centaurea cyanus is recorded in arable fields as very rare and almost extinct, while in the north-east of Ireland it was abundant before the 1930s.

Cultivation

It is grown as an ornamental plant in gardens, where several cultivars have been selected with varying pastel colours, including pink and purple. Cornflower is also grown for the cutflower industry in Canada for use by florists. The most common colour variety for this use is a doubled blue variety such as 'Blue Boy' or 'Blue Diadem'. White, pink, lavender and black are also used but less commonly. Cornflowers germinate quickly after planting.
Light requirements: full sun.
Water requirements: high-average water daily.
Soil pH requirements: neutral to mildly alkaline.

Uses

The edible flower of the cornflower can be used for culinary decoration, for example to add colour to salads. Cornflowers have been used historically for their blue pigment. Cornflowers are often used as an ingredient in some tea blends and herbal teas.
Cornflower seed is one of the favourite foods of the European goldfinch.

Folklore and symbolism

In folklore, cornflowers were worn by young men in love; if the flower faded too quickly, it was taken as a sign that the man's love was not returned.
The blue cornflower has been the national flower of Estonia since 1918 and symbolizes daily bread to Estonians. It is also the symbol of the Estonian Conservative People's Party, the Finnish National Coalition Party, and the Liberal People's Party of Sweden, where it has since the dawn of the 20th century been a symbol for social liberalism. It is the official flower of the Swedish province of Östergötland and the school flower of Winchester College and also of Dulwich College, where it is said to have been the favourite flower of the founder, Edward Alleyn.
The blue cornflower was one of the national symbols of Germany. This is partly due to the story that when Queen Louise of Prussia was fleeing Berlin and pursued by Napoleon's forces, she hid her children in a field of cornflowers and kept them quiet by weaving wreaths for them from the flowers. The flower thus became identified with Prussia, not least because it was the same color as the Prussian military uniform. After the unification of Germany in 1871, it went on to become a symbol of the country as a whole. For this reason, in Austria the blue cornflower is a political symbol for pan-German and rightist ideas. It was worn as a secret symbol identifying members of the then-illegal NSDAP in Austria in the 1930s. Members of the Freedom Party wore it at the openings of the Austrian parliament since 2006. After the last general election 2017 they replaced it with the edelweiss.
It was also the favourite flower of Louise's son Kaiser Wilhelm I. Because of its ties to royalty, authors such as Theodor Fontane have used it symbolically, often sarcastically, to comment on the social and political climate of the time.
The cornflower is also often seen as an inspiration for the German Romantic symbol of the Blue Flower.
Due to its traditional association with Germany, the cornflower has been made the official symbol of the annual German-American Steuben Parade.
In France the bleuet de France is the symbol of the 11 November 1918 armistice and, as such, a common symbol for veterans, similar to the Remembrance poppies worn in the United Kingdom and in Canada.
The cornflower is also the symbol for motor neurone disease and amyotrophic lateral sclerosis.
Cornflowers are sometimes worn by Old Harrovians, former pupils of the British Harrow School.
A blue cornflower was used by Corning Glass Works for the initial release of Corning Ware Pyroceram cookware. Its popularity in the United States, Canada, United Kingdom and Australia was so high that it became the symbol of Corning Glass Works.

In paintings