Annual to perennial herbs (rarely shrubs) without latex; leaves alternate or opposite; heads radiate or discoid, mostly small to medium-sized, some- times large; involucre cylindric to obconic or hemispheric, bracts imbricate, with or without hyaline margins in 1–4 series; receptacles usually naked; ray florets, if present, pistillate, corollas usually yellow to orange or white, sometimes pink to purplish, strap-shaped with usually 2–3 lobes; disc corollas yellow or white, sometimes pink to purplish, with 4–5 lobes of equal or unequal size; an- ther apical anther appendage usually ovate, thecae with- out spurs (ecalcarate) and without tails (ecaudate); pol- len echinate and spherical; styles slender, apices deltate to acuminate with short hairs, style below bifurcation usually glabrous, at maturity style branches recurving; achene walls usually striate, with phytomelanin layer; pappus of scales with thickened base or midrib (if scales not thickened, then disk corollas 4-lobed) or of brown- ish-to-reddish, often fasciculate or hooked bristles.

Diagnostic Features

Combination of epaleate heads; pale or reddish (not blackened) anthers; blackened, stri- ate, usually unflattened achenes; and pappus usually of basally thickened or costate scales or of fascicled or hooked bristles.

Geographic distribution

Mainly southwestern North America (also temperate and montane South America, tropical Africa, and South Pacific).