Shrubs 30–250 cm high, not sprouting following fire. Herbage densely tomentose, aromatic. Leaves cuneate to oblong, 1–4 cm long, 3-lobed distally. Inflorescence paniculate, inconspicuously linear-bracteate. Involucre turbinate, 2.5–4 mm high; outer phyllaries green, tomentose; the inner tan; receptacle glabrous. Disk flowers perfect, 3 to 8, glandular; corolla 1.5–2 mm long. Achenes glandular, sometimes villous, ca. 1 mm long (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX)
We have subspecies tridentata
Beetle & A.M. Young, vaseyana
(Rydb.) Beetle, and (according to Lesica ) spiciformis
(Osterh.) Kartesz & Gandhi.
Usually deep soils of sagebrush steppe, steep open slopes; plains, valleys to subalpine (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX)