Annuals [perennials, shrubs], 5-100+ cm; taprooted. Stems usually 1, erect, branched distally, glabrous or hairy. Leaves basal and cauline; basal sessile or petiolate, distal usually sessile; blades ovate-lanceolate or oblanceolate to lanceolate or linear, margins entire or dentate to pinnately lobed or pinnatisect (faces glabrous or sparsely pubescent or arachnose to villous). Heads borne singly or in loose, corymbiform arrays (terminal heads often surpassed by others). Peduncles not inflated, bracteate. Calyculi of 8-13, linear to filiform bractlets (often intergrading with peduncular bracts). Involucres campanulate, 5-10[-15+] mm diam. (larger in fruit). Phyllaries 20-25+ in 2+ series, lance-linear to linear (± navicular proximally, enfolding ovaries/cypselae of subtended florets, sometimes keeled abaxially), subequal to equal, margins little, if at all, scarious, apices filiform, faces ± arachnose. Receptacles flat, pitted, glabrous, epaleate. Florets 30-100+; corollas mostly yellow (inner sometimes purplish or brown). Cypselae brownish to blackish, ± columnar [obconic], not beaked, ribs or nerves usually 6-8(-10), faces glabrous or ± hirtellous; pappi persistent, of 4-15(-30+), whitish, smooth or barbellulate, setiform scales plus bristles (often equal on outer cypselae and unequal on inner ones). x = 9.