Annual or perennial, aromatic herbs or shrubs with oil glands. Stem erect, simple or distally much branched, glandulose. Leaves mostly opposite, petiolate or sessile, lamina lanceolate to oblanceolate, 1 – 3 pinnatisect, lobes toothed or entire, glabrous or sparsely glandular. Capitula radiate or discoid, big or small,  borne singly on 3 – 10 cm long peduncles or numerous in ± corymbose synflorescence. Involucres narrowly cylindrical or turbinate to broadly campanulate. Phyllaries uni– or biseriate, mostly streaked and/or gland dotted, connate except at apices, persistent. Receptacle convex to conical, pitted or not, epaleate. Ray florets female, fertile  (except in double cultivars), ligules yellow or  orange, red brown or cream, sometimes white in double cultivars. Disc florets bisexual, fertile, 4 – 120 or more. Corollas 5–lobed, greenish, to orange or red–brown, tube much longer than or equalling funnel–shaped throat, lobes deltate to linear–lanceolate. Anthers auriculate at base, style branches truncate, penicillate. Cypselas narrowly obpyramidate or fusiform–terete, longitudinally striate, brown to black, glabrous or hairy. Pappus uniserate of basally connate scales or bristles.

A genus of ca.55 species, distributed in North (SW USA) and South America; 2 species introduced and naturalized in the old world including Pakistan.