Artemisia tridentata, commonly called big sagebrush, Great Basin sagebrush or simply sagebrush, is an aromatic shrub which grows in arid and semi-arid conditions, throughout a range of cold desert, steppe, and mountain habitats in the Intermountain West of North America. The vernacular name "sagebrush" is also used for several related members of the genus Artemisia, such as California Sagebrush (Artemisia californica).
Big Sagebrush and other Artemisia shrubs are the dominant plant species across large portions of the Great Basin. The range extends northward through British Columbia's southern interior, south into Baja California, and east into the western Great Plains of New Mexico, Colorado, Nebraska, and the Dakotas.
Big sagebrush is a coarse, many-branched, pale-grey shrub with yellow flowers and silvery-grey foliage, which is generally 0.5–3 m tall. A deep taproot 1–4 m in length, coupled with laterally spreading roots near the surface, allows sagebrush to gather water from both surface precipitation and the water table several meters beneath. Big sagebrush that is over a meter tall is an indicator of arable land, because it prefers deep, basic soils. Sagebrush is generally long-lived once it makes it past the seedling stage, and can reach ages of over 100 years.
The species has a strong pungent fragrance (especially when wet) due to the presence of camphor, terpenoids and other volatile oils. The taste is bitter and, together with the odor, serves to discourage browsing by many herbivores. It is an evergreen shrub, keeping some of its leaves year-round (although it loses many of them in the late summer). The leaves—attached to the branches at the axillary nodes—are wedge-shaped, 1–3 cm long and 0.3–1 cm broad, with the wider outer tips divided into three lobes (hence the scientific name tridentata). The leaves are covered with fine silvery hairs.
Sagebrush provides food and habitat for a variety of animal species, such as sage grouse, pronghorn, grey vireo, pygmy rabbit, and mule deer. Big sagebrush also creates habitat for many species of grasses and herbs. Besides providing shade and shelter from the wind, the long taproot of sagebrush draws water up from deep in the soil, some of which becomes available to these surrounding shallow-rooted plants
Big sagebrush is used as a herbal medicine by Native Americans throughout the Intermountain West of North America, most notably as a smudging herb. It is also used for preventing infection in wounds, stopping internal bleeding, and treating headaches and colds.
Chemically, the active medicinal constituents include camphor, terpenoids, and tannins. The Navajo use the vapors of sagebrush as a treatment for headache.
The Okanagan and Colville people used sagebrush to smoke hides.
Among the Zuni people, an infusion of the leaves is used externally for body aches. The infusion is also taken as a cold medicine. It is also placed in shoes to treat athlete's foot, fissures between toes, and as a foot deodorant.