Perennials, 10-20(-30) cm across. Stems mostly prostrate (much branched, often forming mats), ± strigoso-sericeous to villous. Leaves sessile; blades oblong, 1-3(-5) cm, 2-3-pinnately lobed. Involucres 4-6 × 7-10+ mm. Phyllaries: margins and apices greenish or lacking pigment, abaxial faces ± villous. Paleae 3-4+ mm, margins greenish or lacking pigment. Ray florets usually 13-21+, rarely 0; laminae 7-10+ mm. Disc corollas 2-3 mm. Cypselae 1-1.5 mm. 2n = 18. Flowering Jul-Aug. Disturbed sites; 10-300 m; introduced; Calif., Conn., Del., Ill., Ind., Md., N.J., N.Y., N.C., Ohio, Wis.; Europe.
From Flora of Indiana (1940) by Charles C. Deam
I found this species in La Porte County, where it covered an acre in very sandy soil in a yard and adjacent nursery. Peattie reported it as escaped in the Calumet District. The plant is used in medicine and cultivated in gardens, especially by people who still grow their own medicinal herbs.