Annuals, (5-)15-35(-90) cm, usually ill-scented. Stems green (sometimes red-tinged), usually erect, branched mostly distally or ± throughout, glabrous, glabrate, puberulent, or sparsely strigillose to strigoso-sericeous (glabrescent, hairs mostly medifixed) and gland-dotted. Leaf blades 25-55 × 15-30 mm, 1-2-pinnately lobed. Peduncles mostly (2-)4-6(-15) cm. Involucres 5-9 mm diam., ± villosulous to arachnose. Receptacles paleate mostly distally; paleae subulate to acerose 2-3+ mm (often gland-dotted). Ray florets 10-15, styliferous and sterile; corollas white, laminae 5-15+ mm. Disc corollas 2-2.5 mm (sparsely gland-dotted). Cypselae 1.3-2 mm, ribs ± tuberculate (furrows often gland-dotted); pappi 0. 2n = 18. Flowering (Apr-)May-Aug(-Oct). Disturbed sites, clearings, fields, roadsides; 10-600(-1500+) m; introduced; Alta., B.C., Man., N.B., Nfld. and Labr. (Nfld.), N.S., Ont., P.E.I., Que., Sask., Yukon; Ala., Alaska, Ariz., Ark., Calif., Colo., Conn., Del., D.C., Fla., Ga., Idaho, Ill., Ind., Iowa, Kans., Ky, La., Maine, Md., Mass., Minn., Miss., Mo., Mont., Nebr., Nev., N.H., N.J., N.Mex., N.Y., N.C., N.Dak., Ohio, Okla., Oreg., Pa., R.I., S.C., S.Dak., Tenn., Tex., Utah, Vt., Va., Wash., W.Va., Wis., Wyo.; Eurasia. Anthemis cotula is a weed throughout North America.

Plant: Annual; herbage ill-scented; stems < 24 cm, erect, generally lightly hairy Leaves: alternate, < 6 cm, 2-3-pinnately divided; segments linear INFLORESCENCE: primary inflorescence a head, each resembling a flower; heads radiate, 1-2.5 cm diam; phyllaries ± 2.5 mm, green, margins scarious, pale brown; receptacle conic, chaffy in upper half, chaff persistent, 2-3 mm Flowers: Ray flowers sterile, 10-15; ligules 6-9 mm, white, reflexed in age; Disk flowers many; corollas yellow; anther tips ovate, bases rounded or ± cordate; style branches truncate with shrub-like tips Fruit: cylindric achene, 1-2 mm; 10-ribbed; ribs with tubercles; pappus a short crown Misc: Weed in disturbed areas, fields, roadsides, coastal dune areas, chaparral, oak woodland; < 2000 m.