Artemisia tridentata

Shrubs, 40-200(-300) cm (herbage gray-haired), aromatic; not root-sprouting (trunks relatively thick). Stems gray-brown, glabrate (bark gray, exfoliating in strips). Leaves persistent, gray-green; blades usually cuneate, (0.4-)0. 5-3.5 × 0.1-0.7 cm, 3-lobed (lobes to ¹/3 blade lengths, 1.5+ mm wide, rounded), faces densely hairy. Heads (usually erect, on slender peduncles) in paniculiform arrays 5-30 × 1-6 cm. Involucres lanceolate, (1-)1.5-4 × 1-3 mm. Phyllaries oblanceolate to widely obovate, densely tomentose. Florets 3-8; corollas 1.5-2.5 mm, glabrous. Cypselae 1-2 mm, hairy or glabrous, glandular. Artemisia tridentata has undergone considerable taxonomic revision in the past century and circumscription of subspecies remains a topic of considerable controversy. Workers in the field should be aware of the morphologic variation within the subspecies across the range of the species (i.e., approximately from the Sierra Nevada in the west to the plains of the Rocky Mountains in the east). Because rangeland managers and conservationists can often identify local morphologic and chemical races based on grazing or habitat preferences of wildlife and domestic animals, some impetus exists to further subdivide the subspecies within A. tridentata at the varietal level. This treatment of the species complex remains conservative in light of the need for further study. As to chemical differences among the subspecies, aroma is often used to distinguish subspecies in the field. Volatile resins in the plants are strongly aromatic and, when crushed, leaves have very distinctive (although not easily described) aromas.

Common Name: sagebrush Duration: Perennial Nativity: Native Lifeform: Shrub General: Shrub, 0.4-3 m (1.3-10 ft) tall, aromatic; trunk thick, somewhat crooked; branches several, spreading to erect; caudex woody, fibrous rooted. Leaves: Cauline (persistent), alternate (often clustered at each node), wedge-shaped in outline, sometimes linear, 0.5-4 cm long, 0.1-1.2 cm wide, grayish green, silky tomentose, apex mostly 3-lobed, the lobes blunt or rounded; blades sessile to short-petiolate. Flowers: Heads numerous, usually erect, arranged in panicle-like arrays on short peduncles; involucre lanceolate, 3-5 mm long; involucral bracts numerous, in 4-7 series, densely tomentose, at least the outer ones; disk flowers only, mostly 3-8, 1.5-2.5 mm long, pale yellow. Fruits: Achene, 1-2 mm long, hairy or glabrous, usually glandular; pappus absent. Ecology: Found in open habitats, slopes, meadows, well-drained soils from 5,000-8,000 ft (1524-2438 m), flowers July- September. Distribution: Apache, Coconino, Mohave, and Navajo counties; western Canada, mid to western U.S. Notes: Four subspecies occur in mid to western North America, two of which have distributions in our range. Ssp. tridentata is a taller shrub (1-3 m tall) with involucres 1.5-2.5 mm long and heads arranged in broad panicle-like arrays. It typically occurs in valley bottoms and on lower slopes along drainages in well-drained soils from 4,000- 7,500 ft (1219-2286 m). Ssp. wyomingensis is somewhat smaller (30-150 cm tall), with heads arrranged in narrow panicle-like arrays. It is characteristic of desert basins, plateaus, and foothills from 2,500-7,500 ft (762-2286 m). Big sagebrush is a drought-tolerant species that grows rapidly and spreads easily from seed, but typically requires the presence of mycorrhizal fungi to establish. Fires of any intensity can kill the plant, and it does not resprout. Colonization after particularly intense fires may be hampered if the soil fungi have been killed as well. Many sagebrush communities in the Great Basin and parts of northern Arizona have been heavily invaded by cheatgrass, and fire regimes have been greatly altered in some of these areas. Ethnobotany: Big sagebrush is an important browse, especially in winter, for many species including pronghorn, sage grouse, and rabbits. It is commonly burned as a smudge to cleanse the air, for ritual purification, and to promote good health. It is also an important source of medicine, soap/disinfectant, and food (seeds), and is used for weaving mats and clothing. Etymology: Artemisia is named for Artemis, the Greek goddess of the hunt and namesake of Artemisia, queen of Anatolia; Editor: Springer et al. 2011