Annual to perennial herbs (rarely shrubs) without latex; leaves alternate (rarely opposite); heads radiate or discoid, mostly medium-sized to large, sometimes small; involucre cylindric to hemispheric, bracts in two or more series, sometimes reflexed, mar- gins (at least of outer) usually not hyaline or scabrous; receptacle usually naked (sometimes with palea-like re- ceptacular outgrowths, rarely truly paleate) and some- times alveolate; ray florets, if present, pistillate or sterile, corollas yellow or white to red or purple, strap-shaped with three lobes, sterile; disc corollas yellow or red to purple, tubular, with five lobes of equal size, lobes usu- ally not longer than wide; anther apical appendage ovate to round, thecae not blackened, without spurs (ecalcar- ate) and with or without short sterile tails (caudate or ecaudate); pollen echinate and spherical; styles slender, branches usually truncate, with terminal tuft of hairs otherwise glabrous or papillose; achenes more or less clavate, glabrous to densely hairy, walls lack phytomela- nin and usually include few, large crystals; pappus of scales or bristles (rarely absent).

Diagnostic Features

Combination of alternate leaves; usually epaleate receptacles; markedly lobed ray corollas; truncate style branches; non-carbonized achenes (with large crystals in achene-wall cells); and scaly pappus.

Geographic distribution

New World (mainly southwestern North America).