The Cornflower Cyanus segetum (syn Centaurea cyanus) is named such because it is found wild in cereal crops. In French it is called le Bleuet. Because of centuries of international grain trading the plant, which is native to Europe, can be found in North America and Australia, its seeds having been carried there in grain cargoes. As an arable weed though, since the mid-20th century it has become much rarer and more localised as a wild flower.
The flowers, which are usually deep blue, can also sometimes be white or pink. The leaves are a bit downy and grey-green. Right now in the Touraine Loire Valley if you know where to look for them the flowers are at their peak, and they will be visible until perhaps July. The Creuse valley, with its sandy alluvial soil and open flat farmland suits them perfectly. The plants are resistant to the current generation of herbicides, and difficult to control mechanically (rather the opposite -- they thrive on the disturbance! and their roots are strong) But earlier herbicides really dealt the population and distribution of this species a blow and modern seed cleaning practices destroyed significant numbers of harvested seed thus preventing them re-entering the natural seed bank. The overuse of nitrogen fertilisers has also caused a decline in cornflower population. Thus in some places you are now more likely to encounter them on roadsides rather than in crops, or they may have been eradicated altogether. In time they could still recover though, because the seeds may well be still viable in the soil, and modern crop rotations favour it. In France, although there is concern about the species and some projects to protect it, it is not considered likely that it will go extinct. In the Touraine the species can be abundant, but to the north, west and south-west the picture is not so good.
The name 'bleuet' to signify this flower first appeared in written French in 1380. Today there seems to be confusion between cornflowers and chicory Chicorium intybus, an abundant blue wild flower found on waste ground throughout France. But chicory has much paler flowers and is a perennial, whereas cornflowers are annuals.
Because of their colour the flowers have been much prized for making garlands, either with the actual flowers, or depicting them in ceramic glazes. They seem to be associated with a remarkable number of political movements, some of them rather nasty, some of them absolutely admirable. Here in France they are best known as the symbol of remembrance for veterans, in the same way that poppies are used in Britain and parts of the Commonwealth. Up until the mid-20th century French mothers would receive red, white and blue bouquets of poppies, daisies and cornflowers on Mothers Day (which is this coming Sunday in France).
The pigment in cornflowers is called protocyanin. It's a type of anthocyanin (a pigment that gives blue, red or purple colours to many plants). Protocyanin expresses as blue in cornflowers but red in roses, for example. The pigment is extracted commercially to colour food products such as yoghurt.
Studies have shown that cornflowers can be useful in taking up lead from contaminated soils, particularly if used in combination with certain fungi or bacteria.
The flowers are edible, although they don't add much in the way of flavour, just the novelty of pretty blue petals scattered on your cheese or ice cream. Traditionally they have been used to make a decoction used as eye drops to treat conjunctivitis, and the science seems to indicate this would indeed have helped.
Cornflowers produce a lot of very sweet nectar so they are very attractive to pollenating bees and flies. The fine seeds they produce are popular with European Gold Finches. They are attractive and easy to grow in your garden, quite dry hardy, and so they are one of the plants I recommend if you are wanting to garden in a wildlife friendly way. Studies have shown that they make an excellent companion plant for brassicas in the garden, because they produce scents attractive to cabbage moth. So plant them amongst your cabbages to lure away cabbage moth. The caterpillars will then be parasitised in greater numbers, and many of the eggs eaten by beetles. Sow the seeds in late spring or early autumn. Deadhead them or pick them for taking indoors to encourage further flowering.
All photos taken by me earlier this week near Chambon in the Creuse Valley.
