Annual or perennial herbs, shrubs, rarely trees. Stem branched, glabrous or pilose. Leaves simple, opposite or alternate rarely whorled, often decurrent along the stem or on a winged petiole, lamina mostly rhombic, deltate, ovate, or elliptic to lanceolate or linear, rarely pinnately or palmately lobed, cuneate to rounded or cordate, margins entire or coarsely serrate, glabrous or hairy. Capitula radiate or discoid, pedunculate, in corymbiform, dichasiform, or paniculiform synflorescence. Involucre cylindrical hemispherical, or campanulate. Phyllaries persistent in 1–4 series, linear, ovate, or oblong to spathulate, lanceolate, or linear, subequal or unequal, outer shorter or longer than inner. Receptacle flat to convex or ± conical, paleate, palea herbaceous, tapering, with broad head. Ray florets white, orange, red, yellow, greenish white, purplish, either female and fertile, or sometimes female but sterile, or neuter, ligules yellow to orange. Disc florets 10–170, bisexual, fertile; corolla usually ± 5–lobed. Style arms long with broadly acute or deltoid apices. Cypselas strongly flattened, orbiculate, obovate, or oblanceolate, winged. Pappus usually of 2, ± subulate, erect awns, rarely uncinate, persistent.

A genus of more than  200 species,  mostly distributed in subtropical, tropical, and warm–temperate North America. Represented in Pakistan by the following introduced/ naturalized species.