Leaves with margins subentire, sinuate, or lobed less than 1/2 distance to midvein; lobes typically subacute to acute at apex, sometimes rounded. 2n = 24.

Phenology: Flowering Apr–Oct.
Habitat: Dis­turbed or urban areas, cultivated fields, light or sandy soils.
Elevation: 0–900(–1200) m.

Distribution

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• Legacy Map

N.S., Ont., Que., Ala., Ariz., Ark., Calif., Colo., 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.Mex., N.Y., N.C., Ohio, Okla., Oreg., Pa., R.I., S.C., S.Dak., Tenn., Tex., Utah, Vt., Va., Wash., W.Va., Wis., introduced in Europe, Asia, Pacific Islands (New Zealand), Australia.

Discussion

In the United States, var. carolinense is apparently native east of the Rocky Mountains and south of the Great Lakes. It is introduced and weedy north and west of its native range in North America. In its native range and elsewhere, var. carolinense is extremely difficult to control in cultivated areas and pastures once established. It has been classified as a noxious weed in several states. All parts of the plant are considered to be toxic and cases of poisoning have been reported in cattle, sheep, deer, and humans (G. A. Wahlert et al. 2015). Some authors recognize two forms: forma carolinense and forma albiflorum (Kuntze) Benke based on violet versus white corollas, but mixed populations occur with both flower colors, so this distinction is not maintained in the latest taxonomic revision (Wahlert et al.).

Selected References

None.

Lower Taxa

None.