Taprooted annual 2-10 dm, the stem bearing spreading glandular hairs below, glabrous above; lvs spreading-hairy like the lower part of the stem, the lowermost ones to 20 נ4 cm, mostly oblanceolate or spatulate, short-petiolate, and coarsely toothed or runcinate-pinnatifid; heads mostly numerous; invol 8-12 mm, glabrous; inner bracts ca 13, generally with raised and thickened, basally expanded midrib; outer bracts very short; receptacle glabrous; fls ca 15-30; achenes 4-6 mm, contracted above but not beaked, stramineous or pale greenish, 10-12-ribbed, the outer ones scabrous-hirtellous; 2n=8. Native of Eurasia, locally established in waste places from Va. to O. and Ind. and southward. May, June.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
This species was found in Jefferson County in 1934 by Miss Edna Banta. She reports that it is a common roadside weed from Eagle Hollow east of Madison eastward along the River Road to Morris Chapel, a mile east of Brooksburg, a distance of about 8 miles. The size and vigor of the plants sent me, being much branched and over three feet high, suggest that it is well established and will be able to compete with any native vegetation and forever be a weed in our state. I collected it in the same area in 1937.