Description from Flora of China
Herbs, annual or perennial, sometimes suffrutescent, glandular pubescent. Leaves alternate, sessile, margin entire or repand-dentate. Capitula solitary, terminal. Involucre campanulate or hemispheric; phyllaries 1- or 2-seriate, lanceolate to linear-lanceolate, acuminate, with scarious margins. Receptacle flat or convex, glabrous, heterogamous. Ray florets female, 2- or 3-seriate, fertile; lamina apically 3-denticulate; style terete, 2-lobed. Disk florets bisexual, functionally male; corolla tubular-funnel-shaped. Style undivided, apically thickened or globose. Achenes polymorphic; outer cymbiform, somewhat curved, rostrate, or triquetrous; inner distinctly curved, sometimes winged, all dorsally rugose to tuberculate-aculeate. x = 7, 8, 9, 11, 15.
About 15 or 20 species: mainly in SW Asia, W Europe, Macaronesia, and Mediterranean region; one species (introduced) in China.