Centaurea jacea is a species of herbaceous

Herbaceous

A herbaceous plant is a plant that has leaves and stems that die down at the end of the growing season to the soil level. They have no persistent woody stem above ground...

 perennial plant

Perennial plant

A perennial plant or simply perennial is a plant that lives for more than two years. The term is often used to differentiate a plant from shorter lived annuals and biennials. The term is sometimes misused by commercial gardeners or horticulturalists to describe only herbaceous perennials...

s in the genus Centaurea

Centaurea

Centaurea is a genus of between 350 and 600 species of herbaceous thistle-like flowering plants in the family Asteraceae. Members of the genus are found only north of the equator, mostly in the Eastern Hemisphere; the Middle East and surrounding regions are particularly species-rich...

native to dry meadows and open woodland throughout Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

. It grows to 10–80 cm tall, and flowers mainly from June to September.
It is mostly found as a hybrid of Black Knapweed, Centaurea nigra

Centaurea nigra

Centaurea nigra is a species of flowering plant in the daisy family known by the common names Lesser Knapweed, Common Knapweed and Black Knapweed...

Unlike the Black Knapweed, the flowerheads always look as if they are rayed, forming a more open star rather than a brush-like tuft.