What is "centaurea cyanus"

Cornflower \Corn"flow`er\ (k[^o]rn"flou`[~e]r), n. (Bot.) A conspicuous wild flower ( Centaurea Cyanus), growing in grainfields.

Centaurea \Cen`tau*re"a\, n. [NL. See Centaury.] (Bot.) A large genus of composite plants, related to the thistles and including the cornflower or bluebottle ( Centaurea Cyanus) and the star thistle ( Centaurea Calcitrapa).

Bluets \Blu"ets\, n. [F. bluet, bleuet, dim. of bleu blue. See Blue, a.] (Bot.) A name given to several different species of plants having blue flowers, as the Houstonia c[oe]rulea, the Centaurea cyanus or bluebottle, and the Vaccinium angustifolium.

Bluebottle \Blue"bot`tle\, blue-bottle \blue-bottle\, n.

1. (Bot.) an annual Eurasian plant ( Centaurea cyanus) which grows in grain fields; -- called also bachelor's button. It receives its name from its blue bottle-shaped flowers. Varieties cultivated in North America have showy heads of blue or purple or pink or white flowers

   Syn: cornflower, bachelor's button.

2. (Zo["o]l.) A large and troublesome species of blowfly ( Musca vomitoria). Its body is steel blue.

Bachelor's button \Bach"e*lor's but"ton\, (Bot.) A plant with flowers shaped like buttons; especially, several species of Ranunculus, and the cornflower ( Centaurea cyanus) and globe amaranth ( Gomphrena).

Note: Bachelor's buttons, a name given to several flowers ``from their similitude to the jagged cloathe buttons, anciently worne in this kingdom,'' according to Johnson's
--Gerarde, p. 472 (1633); but by other writers ascribed to ``a habit of country fellows to carry them in their pockets to divine their success with their sweethearts.''
--Dr. Prior.

Centaurea cyanus, commonly known as cornflower, is an annual flowering plant in the family Asteraceae, native to Europe. In the past it often grew as a weed in cornfields (in the broad sense of the word "corn", referring to grains, such as wheat, barley, rye, or oats), hence its name. 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. 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'. 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.