Perennial or annual herbs. Leaves opposite, entire or divided. Involucrate heads often radiant. Involucral bracts usually herbaceous. Calyx limb of 5 aristate setae. Corolla tubular, 5-lobed. Stamens 4. Involucel 8-grooved or with 8 pits above, expanded above into a scarious corona; the achene adnate to the involucel and crowned by the calyx.