Rhizomatous perennial. Stems simple, erect, 15–90 cm. Herbage tomentose, leaves sometimes glabrate above, aromatic. Leaves cauline, sessile to short-petiolate, 1–9 cm long, linear-lanceolate to obovate, entire, lobed or deeply divided. Inflorescence open to dense, racemose to paniculate, leafy below. Involucre campanulate, 2–5 mm high; phyllaries green to brown, glabrate to tomentose; receptacle glabrous. Disk flowers 10 to 55, perfect and female, glabrous to glandular; corolla 1.5–2.5 mm long; yellow. Achenes glabrous, ca. 0.5 mm long (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX
In addition to the nominal infraspecific taxon, we have the following: A. l.
(Rydb.) D.D. Keck A. l.
(Nutt.) D.D. Keck.