Plants 100-150 cm. Stems simple or distally ± branched, ± white-tomentose, proximally sometimes ± glabrate. Leaves: basal and proximal cauline winged-peti­olate, mid cauline ± clasping; blades elliptic to obovate, margins 2-pinnately divided nearly to midvein, lobes linear to oblong, spiny-serrate, spine-tipped, abaxial faces white-tomentose, adaxial faces green, sparsely viscid-glandular; distal smaller, less divided. Secondary heads 3.5-4.5 cm diam. Involucres 15-20 mm. Inner phyllaries lavender, apices attenuate, serrulate, scabrous, not glandular. Corollas blue to purple (white). Cypselae ca. 6 mm; pappi of ± connate, minutely barbed scales ca. 1 mm. 2n = 32 (Greece).

Flowering summer (Jun-Aug). Disturbed sites; 0-500 m; introduced; N.Y., Wash.; Europe; Asia.

Subspecies ruthenicus sometimes escapes from cultivation.