Plants usually annual, rarely perennial, caulescent, not stoloniferous, 3–45 cm. Stems 1–9, prostrate, decumbent, or erect, simple or branched, subglabrous or puberulent, clustered on taproot. Leaves cauline; stipules palmately lobed or pinnatifid, middle lobe oblanceolate, obovate, elliptic, or lanceolate, sometimes ± equaling leaf blade, margins entire or usually crenate, ciliate, apex acute to obtuse; petiole 1–3.3 cm, glabrous or puberulent; blade ovate to ± oblong (distal blades lanceolate), 1.5–2.8 × 0.8–2.3 cm, base cordate, truncate, or attenuate, margins coarsely crenate-serrate, ciliate or eciliate, apex acute to obtuse, surfaces pubescent abaxially at least on major veins, glabrous adaxially. Peduncles 3–12.5 cm, usually glabrous. Flowers: sepals deltate-lanceolate to linear-lanceolate, margins usually ciliate, auricles 2–4 mm; petals: upper 2 commonly violet, lateral white, and lowest yellow or white on both surfaces with darker yellow patch basally, variants include lateral 2 violet distally or all petals violet, white, yellow, or red, lateral 2 densely bearded, lowest and lateral 2 dark violet- to brownish purple-veined, lateral 2 longer than sepals, lowest 10–15 mm, spur usually yellow to violet, rarely white, elongated, 4–5 mm; style head beardless; cleistogamous flowers absent. Capsules subglobose to ovoid, 6–8 mm, glabrous. Seeds tan, 1.5–2 mm. 2n = 26.

Flowering Apr–Sep. Cultivated and waste ground, roadsides, lawns, urban parks; 10–1000 m; introduced; St. Pierre and Miquelon; Alta., B.C., Man., N.B., Nfld. and Labr. (Nfld.), N.S., Ont., P.E.I., Que., Sask., Yukon; Ala., Alaska, Ark., Calif., Conn., Del., D.C., Fla., Ga., Idaho, Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., Nebr., N.H., N.J., N.Y., N.C., Ohio, Okla., Oreg., Pa., R.I., S.C., Tex., Utah, Vt., Va., Wash., Wis., Wyo.; Europe; Asia (Siberia).

Variety tricolor was introduced from Europe and is not vegetatively distinguishable from Viola arvensis. In Europe, the variety is pollinated mainly by long-tongued bees (A. R. Clapham et al. 1987).