Artemisia arbuscula Nutt. ssp. arbuscula

by Kelly Crowley, Native Plants of Arizona 2004
Common Name: Little sagebrush (1). Gray low sagebrush (2,4). L ow sagebrush
early sagebrush, dwarf sagebrush (3,4). Scabland sagebrush, dark sagebrush (4).
Family: Asteraceae (1).
Synonymy: Artemisia tridentata Nutt. ssp. arbuscula (Nutt.) Hall & Clements, Seriphidium arbusculum (Nutt.) W.A. Weber (1). Artemisia longiloba (Osterh.) Beetle, Artemisia arbuscula var. longiloba (Osterhout) Dorn (3).
Etymology: Artemisia refers to Queen Artemisia of Caria , Asia Minor . Arbuscula means shrubby, small-tree-like (7).

Identification
Growth Form: Perennial shrub (1). Low, spreading, evergreen shrub (5). G enerally growing only 4 to 16 inches (10-40 cm) high (3,5). The species is "evergreen," much-branching, and grows in mounded form (3). Gray low sagebrush is a dwarf, low-spreading, evergreen shrub of irregular form which grows up to 20 inches (5 dm) in height, with a crown spread of 16 to 32 inches (4-8 dm) (4). Roots: Sagebrush may be either arbuscular mycorrhizal or ectomycorrhizal. Low sagebrush has an extensive fibrous root system down to about 8 inches (20 cm); roots are generally tolerant of poor aeration and more efficient at removing water from this soil depth than big or black sagebrush's root systems (3). The fibrous portion of the root system is shallow and fairly extensive, which allows good water absorption (4).
Stem: Light to dark brown bark. The twigs are densely canescent, often later becoming glabrous (5).
Leaves: Leaves are up to 1.5 cm long and variable cleft. Leaves persist through winter and up to mid-season the following year; leaves from the previous year are shed during moisture stress (3). Leaves below the inflorescence canescent, broadly cunate to flabelliform, 5-15 mm long, 3-10 mm wide, usually 3-5 toothed at the apex (5).
Inflorescence/Flowers: The inflorescence is a spike-like, narrow panicle 0.6 inch (1.5 cm) wide. Gray low sagebrush has 4 to 9 flowers per head (3). Inflorescence narrow with mostly few, erect branches; involucre campanulate, 3-4 mm long; 8-12 mostly glabrous phyllaries; flowers mostly 3-5 per head; (5).
Fruit: Achenes glabrous (5).
Similar Species: A. arbuscula may be confused with heavily browsed A. tridentata but can be separated by its narrow spike-like inflorescence.

 Ecology
Life History: Perennial (1). Not much is known of the longevity of low sagebrush but members of the genus are generally long-lived, sometimes up to 150 years (3).
Native/Introduced: Native to the southwest and Midwest United States (1).
Photosynthetic Pathway:
Phenology: August and September with seed ripening in October and November (3).
Distribution: Low sagebrush grows on dry plains and hills (3,4,5). Found in Apache, Navajo and Coconino counties at 6000-8000 ft (5). In the Intermountain region, gray low sagebrush grows most commonly at lower elevations but may be found above 10,000 feet (3,050 m) on warmer and drier site. Low sagebrush grows from California and Nevada north to Oregon and Washington , west through southern and central Idaho and southwestern Montana , and south through Wyoming to Colorado to northern New Mexico . Gray low sagebrush has the same range as the species as a whole (3,4). Gray low sagebrush grows on dry sites from southern Colorado to Montana and westward to northern California , eastern Oregon , and central Washington . It occurs throughout the northern Great Basin , the western part of the Columbia Plateau, in the Cascade and Siskiyou mountains, and the California Coast Range (4).

Uses:
Gray low sagebrush is an important food source for mule deer, pronghorn, sage grouse, and other wildlife species. Gray low sagebrush provides food and cover for a variety of smaller birds and mammals. Domestic livestock utilize gray low sagebrush, although sheep use this species to a much greater extent than do cattle. Sheep prefer gray low sagebrush during the fall and winter. Both cattle and sheep use gray low sagebrush on route to summer range in spring and when leaving in the fall. Gray low sagebrush is rated fair in energy and protein values. Gray low sagebrush can be planted in some areas to minimize soil erosion (4,8).

 References

1.  USDA, NRCS. 2004. The PLANTS Database, Version 3.5 (http://plants.usda.gov) . National Plant Data Center , B aton Rouge , LA 70874-4490 USA .

2.  Integrated Taxonomic Information System (ITIS) ( http://www.itis.usda.gov ).

3.  Steinberg, Peter D. 2002. Artemisia arbuscula. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/ [2004, December 28].

4.  Tirmenstein, Debra A. 1986. Artemisia arbuscula ssp. arbuscula. In: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (2002, April). Fire Effects Information System, [Online]. Available: http://www.fs.fed.us/database/feis/ [2004, December 28].

5.  McDougall, W.B. (1973). Seed Plants of Northern Arizona : With Keys and Detailed Descriptions for the Identification of Families, Genera and Species . Flagstaff : The Museum of Northern Arizona .

6.  Epple, Anne Orth (1995). A Field Guide to the Plants of Arizona . Mesa : LewAnn Publishing Company.

7.  Gledhill, D. (1985). The Names of Plants . Cambridge : Cambridge University Press.