Annuals, mostly with rigid ± erect stems, mostly branched. Lvs alternate, entire or 1-2-pinnate, sometimes palmately lobed. Infl. a dense bracteate head. Bracts leafy, often coriaceous, pungent or spiny. Fls 4-5-merous, sessile or subsessile. Calyx divided almost to base into ± unequal entire or toothed segments; segments united by a scarious membrane in their lower part, accrescent and ruptured by fr. at maturity. Corolla ± funnelform; lobes usually narrow- to broad-oblong. Stamens equally or unequally inserted in throat or in sinuses of corolla lobes, exserted or included. Style included or exserted; stigma entire or 2-3-lobed. Capsule ovoid to obovoid, ± lobed, 1-3-locular. Seeds 1-8 in each loculus, often angled and minutely pitted.