Perennials, 20–80 cm (not cespitose), pleasantly aromatic (fibrous-rooted, rootstocks relatively short, horizontal, layered stems sometimes sprouting). Stems 3–20+, erect, gray-green, usually simple, sometimes branched (bases woody), densely tomentose. Leaves cauline, bicolor (white and green); blades linear to lanceolate, 3–12 × 1 cm, margins usually entire, sometimes toothed or lobed, faces densely tomentose (abaxial) or glabrate (adaxial). Heads (peduncles 0 or to 2 mm) in mostly racemiform arrays 8–13 × 1–2 cm. Involucres campanulate, 4–5 × 4–5 mm. Phyllaries ovate-lanceolate (margins hyaline), densely to sparsely tomentose. Florets: pistillate 3–10; bisexual 8–26; corollas pale yellow, 1–2 mm, sparsely glandular. Cypselae ellipsoid, 0.5–0.8 mm, glabrous. 2n = 36.
Phenology: Flowering mid summer–early fall.
Habitat: Alkaline flats, grasslands, barren areas, high plains
Elevation: 500–1800 m
Alta., B.C., Man., Sask., Idaho, Minn., Mont., Nebr., N.Dak., S.Dak., Wyo.
Artemisia longifolia appears to be more salt-tolerant than most species of the genus. It is closely related to A. ludoviciana.