Annual or biennial, 20 – 100 (–120) cm tall, erect herbs with  stout tap root. Stem and branches spiny−winged up to the base of capitulum, wings 2−10 mm wide, beset with cobwebby hairs. Leaves grey, narrowed to the base, cauline ones basally decurrent, oblanceolate to lanceolate, 5 – 30 cm long, 2 – 15 cm wide, sinuate−pinnatifid, moderately arachnoid beneath with both multicellular and unicellular hairs to tomentose or glabrescent above, with 6 −10 pairs of spines bearing lobes. Capitula terminal in compact clusters of (3−) 4 – 10, ± sessile oblong or narrow cylindrical, ca 2 cm long, 1−1.5 cm broad, rotundate, terminal. Involucre 5−7−seriate, glabrous or sparsely arachnoid; outer and middle phyllaries ovate−lanceolate, ca 1.5 mm wide, acuminate and with  ± outwardly curved spines, inner phyllaries oblong−lanceolate, ± without conspicuous nerve, membranaceous, acuminate.  Corolla pale purplish rarely white, 10−12 mm long, tube 4−8 mm long, limb lobes  3 −5 mm long. Cypselas ellipsoid, 3.5 – 4.5 mm long, pale or greyish−brown with fine, dark longitudinal striations and transverse wrinkles. Pappus 10 – 14 mm long, white – dirty white, scabridulous.