Plants annual herbs, sometimes mat-forming; stems (1-)2-10(-30) cm long, procumbent to erect, glabrous or not. Leaves alternate, usually (1-)2-3 pinnately or pinnati-palmately lobed, distal margins entire or dentate. Heads solitary, axillary, sessile, disciform; involucres hemispheric; phyllaries i5-8 in 1-2+ rows, equal, lanceolate to ovate, margins scarious, at least distally;receptacles convex or conical, without bracts. Flowers without pappuses; marginal flowers pistillate, without corollas, styles sheathed by pericarp tissue, soon becomng indurate and spinelike; disc flowers with yellowish or whitish corollas, 3- or 4-lobed, functionally staminate; anthers obtuse at the base; style branches fused. Achenes flattened, laterally winged, wings sometimes projected, sometimes very narrow, styles peristent and spinescent, sometimes transversely wrinkled to sulcate.
Soliva comprises 6-9 species, depending on whether or not one accepts Webb's (1986) suggestion that the four members of subg. be treated as a single species with variable achene morphology. It has been accepted in this treatment. Soliva is native to South America but several species are now widespread weeds, particularly of lawns.
Webb, C.J. 1986. Variation in achene morphology and its implications for taxonomy in Soliva subgenus Soliva (Anthemideae, Asteraceae), New Zealand Journal of Botany, 24:4, 665-669, DOI: 10.1080/0028825X.1986.10409950
Zhu Shi, Christopher J. Humphries, & Michael G. Gilbert. http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=130663