Artemisia ludoviciana Nutt.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Rhizomatous perennial 3–10 dm, simple to the infl, the stem ± white-tomentose at least above; lvs lanceolate or lance-elliptic, 3–10 cm, entire or irregularly toothed to coarsely few-lobed or deeply parted, the undivided portion to 1(–1.5) cm wide, persistently white- tomentose on both sides or becoming glabrous above; invol 2.5–3.5 mm; disk-cors 1.9–2.8 mm; 2n=18, 36. July–Oct. Prairies, dry ground, and waste places. A widespread, variable sp. of w. U.S. and n. Mex., native e. as far as Ill., and occasionally intr. eastward. Most of our plants are var. ludoviciana, with entire to coarsely few-lobed lvs and a mostly compact and elongate infl. (A. gnaphalodes, the form with the lvs persistently tomentose above; A. herriotii; A. pabularis) Var. mexicana (Willd.) Fernald, with many of the lvs deeply parted and with a strong tendency toward a more diffuse, often leafy infl, is chiefly southwestern, occasionally reaching our range as an introduction. (A. mexicana) Other vars. occur westward.