Annual, biennial or perennial herbs, taprooted or rhizomatous. Lvs 1-3-pinnate or pinnatisect, alternate. Capitula in corymbs, or often solitary, terminal, pedunculate; involucral bracts in 2-5 rows, with membranous margins. Receptacle conic; scales 0. Outer florets ♀, usually ligulate, rarely tubular, usually white, rarely pale pink; inner florets ☿, tubular. Achenes all similar, triquetrous, oblong or obpyramidal; inner surface with 3 ribs; outer surface smooth, rugose, or tuberculate, sometimes ribbed, with (0)-2-(5) glands at apex; pappus usually a small toothed or lobed corona, sometimes 0.