Plants 10-60 cm. Leaf blades lanceolate to broadly ovate, 20-110 × 15-70 mm, margins serrulate to serrate. Arrays of heads loose. Axillary peduncles longer than subtending bractlets. 2n = 16. Flowering summer-fall. Disturbed soils, fields, orchards, gardens, lawns, roadsides; 0-2300 m; introduced; B.C., Man., N.B., Ont., Que.; Ariz., Calif., Colo., Conn., D.C., Ill., Ind., Iowa, Kans., Ky., Md., Mass., Mich., Minn., Mo., Nebr., N.J., N.Y., N.Dak., Ohio, Oreg., Pa., R.I., Tex., Vt., Va., W.Va., Wis.; Mexico; West Indies; Central America; South America; introduced in Europe; Asia; Africa; Australia.