Annual or perennial herbs or shrubs. Leaves opposite or rarely ternate, the upper leaves often alternate, dotted with resin/oil drops on lower leaf surface. Capitula terminal, solitary or in cymes or panicles, radiate; involucre 2-seriate, the outer leafy, the inner grading into the paleae; paleae 3-veined, the inner keeled. Ray florets female with 3-dentate ray; disc florets cylindric, with pubescent tube, 5-lobed; anthers obtuse or sagittate at base, with apical appendage; style arms short and pilose. Achenes black or brown, obovoid to obconical, the ray-floret achenes 3-angled, the inner 4-angled; pappus absent.