Description: Annual, biennial or perennial herbs.
Leaves alternate, entire to toothed.
Inflorescence terminal corymbs; heads hemispherical, yellow-flowered; involucral bracts 4–6-seriate, graduated, ± herbaceous, appressed to spreading at apex; receptacle naked, pitted, flat to convex. Ray florets in 1 row, female fertile, ligulate. Disc florets many, bisexual, tubular-funnelform. Style branches flattened, with a hairy appendage.
Ray achenes compressed-triangular; pappus a short crown, minute bristles or absent. Disc achenes cuneiform; pappus double, of long barbellate inner bristles, and short outer bristles.
Distribution and occurrence: World: c. 7 species, southern & North America & Mexico. Australia: 1 species (naturalized).
Text by M. F. Porteners
Taxon concept:
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