Annual or perennial herbs, rarely shrubs. Stem erect, branched. Leaves usually opposite, rarely alternate or whorled, simple or lobed, petiolate or sessile (leaflets petiolulate), margins entire, dentate, serrate, or toothed, usually glabrous, rarely with hispid hairs. Capitula usually radiate or discoid, sometimes disciform; usually on long peduncles, solitary or in corymbose synflorescence. Involucre mostly hemispheric or campanulate. Phyllaries persistent, mostly biseriate, dimorphic, outer herbaceous, longer or shorter than florets, inner membranaceous, usually distinct, sometimes connate at the base, ovate to oblong–lanceolate. Receptacles flat or slightly convex, paleate, palea green, sometimes yellow to orange, often striated, deciduous. Ray florets yellow, white or pinkish, usually 1–seriate, sterile, sometimes female or neuter. Disc florets bisexual, fertile, yellow, rarely whitish or purplish, corolla tube smaller than (3–) 5–lobed limb. Staminal filaments glabrous. Style branches lanceolate to subulate. Cypselas isomorphic or dimorphic, obcompressed or linear – oblong to ellipsoid 3 – 4 angled, black to reddish brown, glabrous – pubescent, rarely with thickened margins or ± narrowly winged (elsewhere). Pappus of 2–4 usually retrorsely barbed awns.
A medium sized – large genus containing ca 200 species, widespread throughout the world especially in subtropical, tropical and warm–temperate North and South America. Represented in Pakistan by five species.