Annual or perennial herbs or shrubs, glandular, aromatic. Leaves opposite or alternate, sessile or subsessile, simple or lobed. Capitula solitary in leaf axils, small, nodding, discoid, heterogamous; involucral bracts 5, uniseriate, free or connate, herbaceous; receptacle convex, paleate. Outer florets few, uniseriate, female, tubular; corolla filiform (sometimes absent); style branches linear, with subulate papillose terminal appendages. Inner florets functionally male (pistil reduced), tubular, campanulate, 5-lobed; anthers free, sagittate at base with short apical appendage; style short, entire. Achenes enclosed in a very loose conceptacle consisting of the fused involucral bracts, obconical to obovoid, ±compressed, glabrous or hairy. Pappus absent.