Dollar-weed, oreja de ratón, scurfy sida Dollar-weed, oreja de ratón, scurfy sida

Malva leprosa Ortega, Nov. Pl. Descr. Dec. 8: 95. 1798; Disella hederacea (Douglas) Greene; M. hederacea Douglas; M. sulphurea Gillies ex Hooker & Arnott; Malvastrum sulphureum (Gillies ex Hooker & Arnott) Grisebach; Sida hederacea (Douglas) Torrey ex A. Gray; S. leprosa (Ortega) K. Schumann; S. sulphurea (Gillies ex Hooker & Arnott) A. Gray

Stems prostrate, indument mixture of stellate and appressed, sublepidote hairs. Leaves: petiole 1/2–1 times as long as blade; blade ± reniform, 1–3.5 cm, wider than long, base obliquely truncate, margins serrate, apex obtuse or subacute, surfaces densely hairy, hairs appressed, sublepidote and stellate. Pedicels long, subequal to subtending petiole; involucellar bractlets 3, inconspicuous, filiform, or 0. Flowers: calyx 8–10 mm, with mixture of stellate and appressed sublepidote hairs, lobes ovate, bases not plicate-overlapping, apex acuminate; petals pale yellow, sometimes with rose flush on fading, asymmetric, 12–15 mm; stamens pallid, glabrous, staminal column antheriferous at apex; style 7–10-branched, pallid, glabrous. Schizocarps 7 mm diam. 2n = 22, 32.

Flowering year-round in warmer areas. Heavy, saline soil; 800–1500 m; Ariz., Calif., Colo., Idaho, Kans., Nev., N.Mex., Okla., Oreg., Tex., Utah, Wash.; Mexico (Baja California, Chihuahua, Coahuila, Durango, San Luis Potosí, Sinaloa, Sonora); South America (Argentina, Chile, Peru, Uruguay).

Malvella leprosa is possibly introduced in Colorado. The species is considered to be a noxious weed in Arizona and California and increasing as saline soils increase.