Perennials, 50-180(-250) cm, aromatic (rhizomatous). Stems 1-20, erect, brown to gray-green, simple, hairy or glabrescent. Leaves cauline, bicolor (white and green to light gray-green); blades narrowly elliptic to widely oblanceolate, (1-)3-11(-15) × 0.5-2(-6) cm (proximal with 3-5 lateral lobes, distal mostly entire), faces sparsely tomentose (abaxial) to sparsely hairy (adaxial). Heads (usually nodding) in (leafy) paniculiform arrays 10-30 × 3-9 cm (branches widely spreading, ascending, stout). Involucres narrowly turbinate to campanulate, 2-3 × 2-4 mm. Phyllaries (green to gray) ovate, tomentose to pubescent. Florets: pistillate 6-10; bisexual 6-25; corollas pale yellow, 1-1.5 mm, glabrous, sometimes glandular. Cypselae ellipsoid, 0.5-1 mm, glabrous. 2n = 54.
Flowering mid spring-late fall. Meadows, shaded sites, along drainages; 100-2200 m; Calif., Nev., Oreg., Wash.
Artemisia douglasiana is sometimes weedy. Reports from areas outside the northwestern portion of the United States are based on misidentifications of plants in the A. ludoviciana complex.