Chaenactideae

Annual or perennial herbs (rarely subshrubs) without latex; leaves usually alternate; heads discoid, small to medium-sized; involucre cylindric to more or less broadly campanulate, bracts 1–2-seri- ate without hyaline margins; receptacle naked (rarely partially paleate), smooth; corollas of peripheral florets sometimes zygomorphic, corollas white to reddish or yellow with five lobes of equal or unequal size (periph- eral lobes sometimes enlarged); anther apical append- age more or less round to ovate, thecae not blackened, without spurs (ecalcarate) and without tails (ecaudate); pollen echinate and spherical; styles slender, apices usu- ally acute with short hairs, glabrous or hairy below style bifurcation, at maturity style branches recurving; achene walls striate, with phytomelanin layer; pappus of setose to obovate scales without thickened bases or midribs and sometimes fused at base into deciduous unit.

Diagnostic Features

Combination of alternate, often lobed, leaves; discoid heads; epaleate receptacles; pale or reddish (not blackened) anthers; more or less terete (not flattened), striate achenes; and unribbed and unthickened pappus scales, sometimes deciduous as a unit.

Geographic distribution

Western and southwestern North America, mainly California.