Tuesday, March 20, 2007


Sagebrush, or Big Sagebrush is the common name for Artemisia tridentata, a shrub or small tree from the composite family (Asteraceae). The name sagebrush is also used for several related members of the genus Artemisia, such as California Sagebrush It is a coarse, hardy silvery-grey bush with yellow flowers and grows in arid sections of the western United States. It is the main vegetation across vast areas of the Great Basin desert. Along rivers or in other relatively wet areas, sagebrush can grow as tall as 10 feet (3 meters).
Sagebrush has a strong pungent fragrance, particularly when wet, which is not unlike common sage. It is, however, dissimilar to common sage and has a bitter taste. It is thought that this odor serves to discourage browsing.
Sagebrush leaves are wedge-shaped, and are attached to the branch by the narrow end. The outer and wider end is usually divided into three lobes (although leaves with two or four lobes are not uncommon), hence the scientific name tridentata. The leaves are enclosed with fine silvery hairs, which are thought to keep the leaf cool and minimize water loss. Most of the leaves are carried year-round, as sagebrush tends to grow in areas where winter precipitation is greater than summer precipitation.
sagebrush leaves compare favorably to alfalfa for livestock nutrition value. However, they also have oils that are toxic to the symbiotic bacteria in the rumen of most ruminants. These oils have the most effect on cattle. Cattle that resort to sagebrush due to the lack of other fodder in the winter often freeze to death before starving, as they rely in large part on the heat of their digestive action for warmth. Ranchers call this condition "hollow belly". Sheep can stand moderate consumption of sagebrush leaves, especially the fresh spring buds. Pronghorn are the only large herbivore to browse sagebrush extensively. As pronghorn are the only remaining big herbivore that evolved along with sagebrush (deer are a more recent arrival from Asia), this is not surprising. There is speculation that some of the herbivores that went extinct in North America at the end of the Pleistocene such as the Ground Sloth or the American Camel were also capable of browsing sagebrush.
Sagebrush flowers in the late summer or early fall. The flowers are yellow and are carried in long, slender clusters.

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