Carpet burrweed

Hippia stolonifera Brotero, Phytogr. Lusitan. Select., no. 14. 1801; Gymnostyles nasturtifolia Jussieu; G. stolonifera (Brotero) Tutin; Soliva nasturtifolia (Jussieu) de Candolle

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.