Annuals, 10-60 cm (herbage sweet scented). Stems (1-10) erect or ± decumbent, unbranched or sparingly branched distally, sparsely to densely pilose. Leaves cauline; alternate; petiolate; blades lanceolate, oblanceolate, ovate, or spatulate, margins entire, faces usually sparsely to moderately pilose (especially on margins), sometimes glabrate or glabrous. Heads radiate, borne singly or (2-45) in paniculiform arrays. Involucres hemispheric to globose, 12-20 mm diam. Phyllaries persistent, 17-21 in 2 series (outer usually distinct, sometimes connate proximally, green, narrowly elliptic to lanceolate, herbaceous, moderately to densely pilose, especially bases and margins; inner phyllaries distinct, obovate, hyaline, scalelike, glabrous). Receptacles globose to ovoid, ± pitted, usually epaleate (outer disc florets rarely subtended by paleae, central disc florets usually subtended by persistent enations). Ray florets 8-13(-20), pistillate, fertile; corollas yellow. Disc florets 20-50, bisexual, fertile; corollas yellow, tubes shorter than narrowly funnelform to cylindric-campanulate throats, lobes 5, ± deltate (glabrous). Cypselae narrowly obconic, prominantly 10-ribbed, densely pubescent; pappi persistent, of 5-6 ovate to obovate scales. x = 19.