Biennial herb; stems spiny-winged, branched above, 0.3-1.5 m tall.
Basal leaves lacking; stem leaves narrowly elliptic or oblong in outline, deeply lobed or pinnately cut, up to 25 cm long and 8 cm wide, sparsely hairy on main veins, spiny-margined.
Heads discoid, 1.5-2.5 cm wide, clustered or solitary and erect at the ends of branches; involucres hemispheric; involucral bracts linear-lanceolate, in 2-3 series, somewhat leafy and spreading, outer ones spine-tipped; disk flowers usually purplish, sometimes cream or white, nearly 2 cm long.
Achenes glabrous, egg-shaped, with 15-20 dark longitudinal lines and a lighter collar at the tip; pappus whitish with minutely finely-barbed bristles.
If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.
Illustration Source: The Illustrated Flora of British Columbia