Annual or perennial herbs, shrubs, or trees without latex; leaves usually opposite; heads ra- diate (rarely discoid), size varies; involucre obconic to hemispheric, bracts in 1–5 series; receptacle paleate; ray florets pistillate (rarely sterile), ray corolla usually yellow or white, strap-shaped with three lobes or limb some- times absent, sterile; disk florets bisexual or functionally staminate, corollas yellow with (4–)5 lobes of equal or sometimes unequal size; anther apical appendage usually lanceolate to ovate, thecae usually blackened, sometimes pale (green in Guardiola), without spurs (ecalcarate) and tails (ecaudate); pollen echinate and spherical; styles slen- der, apices of branches often acute to penicillate, with short hairs, remainder of style glabrous, at maturity style branches erect or recurving; achenes usually more or less terete, achene walls usually striate, with phytomelanin layer; pappus absent or of scales or bristles.

Diagnostic Features

Combination of usually opposite, often glandular leaves; scarious paleae; usually blackened anther thecae; more or less terete, usually striate, black- ened achenes; and radially-arrayed (or absent) pappus scales or bristles.

Geographic distribution

Mainly Mexico and northern Andes (also Old World tropics, especially Africa).