Hairy or glabrous, annual, biennial or perennial herbs, sometimes woody at base. Leaves alternate, uni- to tripinnatisect or partite, primary segments divided into linear or lanceolate-spathulate ultimate segments. Capitula usually solitary terminal, rarely in corymbs, pedunculate, mostly radiate, occasionally discoid, heterogamous. Involucre of 3-many-seriate, imbricate, membranous and entire or lacerate margined phyllaries. Receptacle conical to hemispherical, beset all over or in the upper part only with rigid, subulate or lanceolate to ± spathulate, mucronate or acuminate-spinescent paleae. Ray-florets uniseriate, female, rarely neuter, fertile or sterile, with terete or compressed corolla tube and 2-3-dentate, white or purplish, reflexed ligule. Disc-florets hermaphrodite, fertile, corolla tube compressed and 2-winged or inflated at the base, with 5-dentate limb; anther bases entire, obtuse; style branches flattened, truncate and penicillate at apices. Cypselas cylindric-oblong to obpyramidate, 4-5-angled or 8-10-ribbed or multistriate, smooth or tuberculate, bald or beset apically with a short dentate rim or membranous, entire or lacerate auricle on one side.