Perennials, 10-60 cm. taproots vertical, thick, caudices woody. Stems erect, simple or branched distally, glabrous or sparsely hairy proximally. Leaves basal and proximally cauline; basal blades narrowly oblanceolate, 40-102(-250) × 10-50 mm, margins entire to sharply dentate or deeply pinnatifid (lobes long and narrow, ciliate), faces glabrous or ± glabrate; (cauline blades not clasping, distally reduced, margins shallowly dentate to coarsely pinnatifid). Heads borne singly or 2-13 in paniculiform to corymbiform arrays. Involucres cylindric or narrowly campanulate, 8-15(-18) × 5-10(-12) mm. Phyllaries 20-24, narrowly lanceolate, 1-14 mm, unequal, margins scarious (apices darkened), faces glabrous or sparsely tomentulose. Florets 50-100+; corollas white, 5-7 mm, not surpassing phyllaries at flowering. Cypselae monomorphic, all beaked (beaks 4-5 mm). bodies brown. fusiform, 7-8 mm, 10-nerved. muricate-roughened; pappi of white, plumose bristles in 1 series, 7-8 mm. 2n = 8, 10. Flowering Apr-May. Grazed woodlands, stream bottoms, ditches, sandy or silty soils; 1-50 m; introduced; La., Okla., Tex.; South America.