Usually glabrous annual or biennial. Stems ascending, not or sparingly branched, glabrous, grooved, 40-60 cm tall. Lvs green, glabrous or sometimes with spines along midrib beneath. Rosette and lower stem lvs green, tapering to base, 3-10 × 1-2 cm, pinnatifid; lobes slender, linear, acute, recurved, entire. Upper lvs sessile, linear, hastate and amplexicaul at base. Infl. spicate. Capitula numerous. Involucre narrowly cylindric, 8-15 mm long; bracts imbricate, erecto-patent at fruiting; outermost bracts lanceolate, acuminate, 1/5-1/6 length of innermost bracts; innermost bracts linear, subacute to acute. Florets c. 11/2× length of involucre; corollas suberect, pale yellow. Achenes pale brown or grey, 7-8-ribbed on each face, obovate, flattened, scabrid distally on ribs; body 3-4 mm long; beak pale, 11/2-2× length of body. Pappus fine, white.