A coarse perennial herb up to 2 m tall, stem stout, simple below branching above into the compound inflorescence, loosely white-cobwebby on the younger parts, beset with slender spines up to 7 mm long, narrowly winged, leafy. Leaves up to c. 15 x 7 cm, elliptic in outline, lowermost narrowed to a spiny, petiole-like base, upper sessile, all decurrent on the stem in narrow spiny wings, apex acute, spiny, margins deeply toothed, teeth paired or in threes, triangular, spine-tipped, margins with slender spines, upper surface thinly cobwebby at first, soon harshly puberulous, lower surface white-felted. Heads 3.5-5 cm across the expanded rays, paniculately or subcorymbosely arranged. Involucral bracts linear-lanceolate, up to 2 mm broad, tip and margins spiny, white-tomentose on the back. Rays and disc yellow. Achenes 2 mm long, turbinate, glabrous. Pappus scales less than 1 mm long, obtuse.
Coarse, perennial herb, up to ± 2 m high; stem stout, simple below branching above into the compound inflorescence, beset with slender spines, narrowly winged, leafy. Leaves elliptic in outline, lowermost narrowed to spiny, petiole-like base, upper sessile, apex acute, spiny, margins deeply toothed, teeth paired or in threes, triangular, spine-tipped, margins with slender spines. Capitula paniculately or subcorymbosely arranged; involucral bracts linear-lanceolate, tip and margins spiny, white-tomentose on the back. Ray florets yellow. Disc florets yellow. Flowering time Jan.-Mar. Pappus of obtuse scales. Cypselae turbinate, glabrous.