Annuals, 10-120(-300+) cm. Stems erect, distally branched. Leaves cauline; mostly alternate (distal sometimes opposite); petiolate (proximal) or sessile; blades mostly lanceolate, oblanceolate, or ovate, bases mostly cuneate, margins coarsely toothed to crenate or ± entire, faces ± scabrellous and/or ± hispid. Heads radiate, borne singly or in (leafy to bracteate) loose, corymbiform arrays. Involucres ± turbinate to hemispheric, 5-12 mm diam. Phyllaries persistent (outer), (8-)10 in 2 series (outer 4-5 becoming reflexed, usually lance-linear, narrower and shorter than inner). Receptacles an outer ring supporting ray florets plus an inner column supporting disc florets, paleate (paleae linear, conduplicate). Ray florets (4-)5, pistillate, fertile; corollas lemon to bright yellow. Disc florets 12-25+, functionally staminate; corollas dull yellow to brownish, tubes shorter than funnelform throats, lobes 5, deltate. Cypselae obcompressed, oblanceolate to obovate (winged, faces ± scabrous to scabrellous; each shed with its subtending phyllary and 2 contiguous paleae with their florets); pappi 0 (shoulders of cypsela wings often projecting as deltate to cornute processes, sometimes interpreted as pappus). x = 8.