Slender knapweed

Centaurea debeauxii, commonly known as slender knapweed or meadow knapweed (in part), is a perennial herb in the family Asteraceae native to western and central Europe and naturalised in parts of North America. It typically grows 30 to 100 cm tall on slender, branched, somewhat wiry stems arising from a stout taproot. The lower leaves are oblanceolate and sometimes shallowly lobed, while the upper stem leaves are smaller, linear-lanceolate and entire. The flower heads are solitary at branch tips, with a rounded involucre of bracts whose papery, finely fringed appendages are pale brown and conspicuous. The disc florets are pink to purple, with the marginal florets often enlarged and ray-like though sterile. It is closely related to and frequently confused with Centaurea jacea and C. nigra, with which it hybridises freely; the resulting hybrid complex (sometimes called C. x moncktonii or meadow knapweed) is widespread in pastures, meadows, roadsides and waste ground.