These are the cornflowers and knapweeds, with very characteristic composite heads of long-petalled outer, sterile, florets and a boss of shorter, fertile florets. This array is surrounded by neatly overlapping bracts, hairy at the upper edge. There are hundreds of species of Centaurea in Europe, so identification is often difficult.
Centaurea stricta is an erect knapweed from Macedonia, bearing blue flower heads standing above wooly, grey green leaves.