Usually spiny, branched annuals, rarely perennial and woody at the base, with glandular and more or less villous-lanate to arachnoid indumentum.
Leaves usually pinnatifid to pinnatisect, with spiny margin.
Involucral bracts in many rows, imbricate, spiny, the outer leaf-like, the inner sometimes with apical appendages. Capitula solitary on stems and branches. Filaments usually densely bearded. Achenes oblong to obpyramidal, 4-angled, glabrous, the outer usually coarsly rugose, without pappus, the inner more or less smooth, usually with a persistent pappus of many rows of linear scales.