Plants 2-5(-15+) cm (high or across), ± strigillose to villous (stems procumbent, rooting at nodes). Leaves basal and cauline, blades ± spatulate, 1-2(-3) cm, 1(-2)-pinnati-palmately lobed. Heads mostly scattered along stems. Involucres 3-6(-8) mm diam. Pistillate florets (20-)40-60+ in 2-4+ series. Disc florets 4-6+; corollas 1.5-2 mm. Cypselae: bodies oblanceolate to oblong-cuneate, 1.8-2.2 mm, wings transversely rugulose or ribbed on proximal 9/10, shoulders ± spinose laterally, faces distally villous to pilose or arachnose; pappi 0 (persistent stylar sheaths indurate, spinelike, 0.8-1.5 mm, usually inflexed). 2n = ca. 114 (as S. nasturtifolia).
Flowering Mar-Apr(-Aug). Disturbed sites; 10-100+ m; introduced; Ala., Ark., Fla., Ga., La., S.C., Tex.; South America; introduced also in Europe.