Annuals, perennials, or subshrubs, to 200+ cm [trees to 400 cm] (usually ± succulent, herbage usually glaucous). Stems (often purplish) erect or decumbent, branched distally or ± throughout. Leaves cauline; opposite (decussate); petiolate or sessile (weakly connate to connate-perfoliate); blades (often 3-nerved) oblong-ovate to lanceolate or linear, margins entire, serrate, or spinulose-serrate, faces glabrous or short-pubescent. Heads radiate or discoid, usually in tight or loose aggregations in (often flat-topped) ± corymbiform arrays or glomerules. Involucres oblong, urceolate, cylindric, or turbinate, 0.5–2 mm diam. Phyllaries persistent, 2–6(–9) in ± 1 series (linear, concave, or boat-shaped, subequal). Receptacles convex, epaleate (“receptacles” of glomerules sometimes setose). Ray florets 0–1(–2), pistillate, fertile; corollas yellow or whitish (laminae inconspicuous). Disc florets 1–15, bisexual, fertile; corollas yellow, tubes shorter than to about equaling funnelform to campanulate throats, lobes 5, ± deltate. Cypselae (black) weakly compressed, narrowly oblanceolate or linear-oblong (usually 10-nerved, glabrous); pappi usually 0, sometimes persistent, of 2–4 hyaline scales, or coroniform (of connate scales). x = 18.