Cornflower, Bachelor's buttons, Star thistle
Cyanus segetum

Family: Asteraceae

What it is like

An annual plant. The stems are slender. It usually branches higher up. It has a grey-cottony appearance. It grows 30-90 cm high and spreads 20-40 cm wide. The leaves are narrow and blue-green. They may have small teeth. The lower leaves may have a few narrow lobes. The flowers are blue. The heads are 15-30 mm across. The flower heads occur singly. The outer florets spread much wider than the inner ones. The flower bracts have a fringe of brown or silver.

There are 400 to 600 Centaurea species. It can become invasive.

Where it is found

A temperate plant. It grows in cereal fields and waste and cultivated ground. It suits hardiness zones 2-10. It needs to be planted after frosts. It needs well drained soil and cannot tolerate wind. Plants do best with a pH of 6.0-7.0. They need a temperature between 10°-30°C.

Countries/locations it is found in

Argentina, Armenia, Asia, Australia, Belarus, Britain, Caucasus, Chile, China, Dominican Republic, Europe, Hawaii, India, Mediterranean (country/location of origin), North America, Norway, Pacific, Poland, Russia, Scandinavia, South America, Tasmania, Turkey, Türkiye, USA, Yugoslavia, West Indies

How it is used for food

The flowers have been used to give blue colour to desserts. They are also cooked and eaten or added to beer. They are added to salads and cooked dishes to add decoration. The flowers have sugar added and used to make wine.

Edible parts

Flowers

How it is grown

It can be grown by seed.

Its other names

Local names

Bluebottle, Kornblom, Terepuk kapuyt, Vasilki

Synonyms

Centaurea concinna (Boiss. & A. Huet.) Trautv.; Centaurea cyanus L.; and others