Somewhat fleshy glab. perennial herb with stems branched from base. Stems and lowest branches decumbent, creeping and rooting, then erect to ascending, up to 3 dm. tall, but often reduced to < 10 cm. under adverse conditions. Lamina (12)-50-80 mm. long, entire, narrow-oblong to lanceolate, widened to amplexicaul base; or more usually irregularly pinnatifid with 3 to many pinnae or lobes. Scapes slender, axillary and terminal, of diverse length. Capitula ± 8-10 mm. diam.; phyll. membr., narrow-oblong, obtuse; receptacle ± convex, finally us. strongly so. Florets bright yellow, ♀in 1 series on slender flattened pedicels; disk-florets perfect, us.∞, hardly pedicelled. Achenes broad-cylindric, ± compressed, with broad spongy wings.

2n = 20

2n = 20

Ascending to erect, fleshy, glabrous annual or short-lived perennial up to 30 cm tall. Stems terete, branched from base and above, up to 25-(40) cm long, rooting freely from lower nodes. Lvs fleshy, alternate, apetiolate, linear, lanceolate or spathulate, entire, with few irregular large lobes, or shallowly 1-(2)-pinnatisect, usually perfoliate, rarely amplexicaul, (10)-15-80 mm long; lvs above becoming shorter, more triangular, less often divided and more often amplexicaul. Involucral bracts in 2-3 rows, 4-6 mm long. Capitula solitary, bright yellow, (6)-8-10-(13) mm diam.; peduncles scarcely expanded at apex, solid, 2-7 cm long, c. 1 mm diam.; ♀ florets in 1 or < 1 row, pedicellate, with a corolla; ☿ florets numerous, subsessile, with flattened tubular corolla. Achenes all flattened, hairy on inner surface, glabrous on outer. Achenes of ♀ florets 1.5-2 × 1-1.2 mm; lateral angles with thick, corky, entire, marginal wings. Achenes of ☿ florets 1.1-1.2 × 0.5-0.6 mm; lateral angles thinly ribbed.