Centaurea montana

Centaurea montana (perennial cornflower, mountain cornflower, bachelor's button, montane knapweed or mountain bluet) is a species of Centaurea endemic to Europe. It is widespread and common in the more southerly mountain ranges of Europe, but is rarer in the north. It escapes from gardens readily, and has thereby become established in the British Isles, Scandinavia and North America.