Centaurea montana

Erect, rhizomatous or stoloniferous perennial to 80 cm tall. Leaves ovate, elliptic or lanceolate, 5–30 cm, 1–8 cm wide, margins entire or dentate to pinnately lobed, acute, puberulous, decurrent. Capitula solitary, ovoid to campanulate, 15–25 mm diam.; involucre 15–25 mm long; intermediate involucral bracts ovate to lanceolate, glabrous or with few long soft hairs, margins dark brown or black, dentate, elongated at the apex into a terminal appendage to 2.5 mm; inner involucral bracts longer with green basal margins. Corolla 2.5–4.5 cm, blue (also white, purple and pink in overseas material). Cypselas 5–6 mm, brown, sericeous; pappus of bristles 0.5–1 mm long.  Flowers summer.