Taprooted biennial. Stems branched, with soft multicellular and fine cobwebby hairs, (20)-50-150-(200) cm tall, ribbed, with broad, dentate, spiny wings between lf bases. Lvs oblanceolate or narrowly oblanceolate, deeply pinnatifid (subentire to shallowly pinnatifid in seedlings), dark green above, paler beneath, (7)-10-30-(40) × 4-10-(20) cm, with short, stiff, pale, spinous bristles above and dense cobwebby tomentum beneath; lf lobes deltoid to lanceolate to linear; prickles pale, 4-10 mm long. Subfloral lvs linear, short to long, sometimes investing capitula. Capitula ovoid, waisted at flowering, erect, 2.5-6 × 2.5-5 cm, solitary or in clusters of 2-3; peduncles 0-2 cm long. Outer involucral bracts linear, with cobwebby margins; apex acuminate, with strong spine 3-4-(6) mm long, recurved to patent. Inner involucral bracts linear, becoming ciliate; apex acute, not spinous, erect. Corolla purple, 28-33 mm long; lobes 5-6 mm long. Style exserted c. 3 mm beyond corolla lobes. Achenes pale, narrowly obovoid, c. 4 × 1.5 mm; pappus 20-25 mm long; cilia on pappus bristles 5-6 mm long.