Slender erect to spreading annual to biennial herb with simple or sparingly branched, sulcate, nearly glab. stems up to ± 5 dm. tall, us. shorter. Lower lvs crowded, ± 7-15 × (2.5)-5-6 cm., including petiole = or < lamina. Lamina lyrate, membr., glab. or nearly so, us. purplish below, broad-ovate to oblong to obovate in outline. Terminal lobe large, obtuse, shallowly to rather deeply lobulate; lobules rounded, apiculate. Petiole narrowly winged with or without one or more pairs of oblong to broad-ovate lobes, these with coarse rounded apiculate lobules or entire, ciliolate, semiamplexicaul and auriculate at base. Mid lvs similar, ± oblong in outline, more deeply lobed; uppermost narrow-oblong, pinnatifid. Infl. a subcorymbose lax panicle; bracts filiform to linear-subulate, c. 3-5 mm. long. Capitula, often few, c. 9 mm. long; phyll. 10-14, c. 6 × 0·5 mm. with 2-nerved keel, margins broadly scarious. ♀ ± 10-15, occ. bearing staminodes, style-arms glab. or nearly so, corolla filiform, c. 4 mm. long, teeth 4; perfect florets with style-arms sparsely hairy, corolla narrow-funnelform, 5-toothed. Achenes 3-4 mm. long, glab., grooved, narrowed to very short beak. Pappus-hairs fine, white, c. 6 mm. long.

2n = 40

Erect annual to short-lived perennial herb. Mid cauline lvs almost glabrous or with few scattered hairs on both surfaces, apetiolate or cuneately narrowed to appear petiolate, narrow-oblong, elliptic, or narrow-obovate, shallowly pinnately lobed and denticulate to lyrate-pinnatifid or 1-pinnatifid with ± oblong, few-toothed (rarely many-toothed) segments, amplexicaul and dentate at base or rarely not amplexicaul, (4)-6-13 × (1)-2-5 cm. Uppermost lvs smaller, often lanceolate, usually 1-pinnatifid, sometimes only dentate or entire. Supplementary bracts 3-6, 1-2 mm long. Involucral bracts (8)-12-13-(14), glabrous, 6-7-(8) mm long. Ray florets 0. Disc yellow, 2-3 mm diam. Achenes subcylindric, narrowed to and constricted below apex, glabrous or with scattered hairs in 1-3 rows in narrow grooves between broad ribs, (2.2)-3-4-(5) mm long.