Annuals, 5–100 cm (taproots slender). Stems 1, erect, simple, proximally hispid and stipitate-glandular (viscid), distally glabrous. Leaves basal and cauline; petiolate; blades oblanceolate or runcinate, 1–24 × 1–5 cm, (bases attenuate) margins deeply pinnately lobed to denticulate (lobes triangular, terminal lobes largest), apices obtuse to acute, faces densely stipitate-glandular (viscid). Heads 10–40, in loose, corymbiform arrays. Calyculi of 5–7, ovate or lanceolate, glabrous bractlets 1–2 mm. Involucres cylindric (turbinate in fruit), 8–12 × 3–5 mm. Phyllaries 10–14, (green medially) lanceolate, 8–10 mm, (bases strongly keeled and thickened, margins scarious), apices acute, faces glabrous. Florets 15–30; corollas light yellow, 5–12 mm. Cypselae (monomorphic or dimorphic) green to yellowish brown, subcylindric, outer 5–6 mm, inner 4–5 mm, apices attenuate (not beaked), ribs 10–12; pappi dusky white (very fine, fluffy), 4–5 mm. 2n = 8.
"Taprooted annual 2–10 dm, the stem bearing spreading glandular hairs below, glabrous above; lvs spreading-hairy like the lower part of the stem, the lowermost ones to 20 × 4 cm, mostly oblanceolate or spatulate, short-petiolate, and coarsely toothed or runcinate-pinnatifid; heads mostly numerous; invol 8–12 mm, glabrous; inner bracts ca 13, generally with raised and thickened, basally expanded midrib; outer bracts very short; receptacle glabrous; fls ca 15–30; achenes 4–6 mm, contracted above but not beaked, stramineous or pale greenish, 10–12-ribbed, the outer ones scabrous-hirtellous; 2n=8. Native of Eurasia, locally established in waste places from Va. to O. and Ind. and southward. May, June."