The Sagebrushes of the genus Artemisia are members of the Asters, the largest of Dicotyledoneae flowering plant families. Although having a similar aroma, they are not closely related to the true sages (Salvia species) of the mint family, Labiatae. There are both native and introduced members, with at least 19 species found within the United States. A dozen species are found in the western states, with fewer in the eastern states. The most prevalent eastern sage is the introduced European weed, annual mugwort, Artemisia vulgaris. Giant sagebrush, A. tridentata, is a native especially prevalent west of the continental divide. It is a woody perennial reproducing by seed, and suited to the arid environment of the Rocky Mountain and Great Basin regions. It is the most abundant western shrub and constitutes the dominant vegetation for great expanses in the mountain states. It will grow in elevations from 3,000 to 8,000 feet and to timberline in Colorado. Average height is approximately 3 feet, but in deep soil it may grow to > 10 feet, with trunks >3 inches in diameter. The bark is gray-brown and stringy. The leaves are small, silvery blue-gray because of dense gray hairs. There are three shallow scalloped teeth at the end, giving the plant its species name, tridentata. Although not preferred by livestock, its high protein, carbohydrate, and fat content make giant sagebrush excellent winter-feed.

Wodehouse felt giant sagebrush to be a significant inducer of hay fever throughout the western United States. Giant sagebrush produces so much pollen that when the wind blows, small yellow clouds are easily discernible. Pollen anthesis for giant sagebrush is between July and September in the north-central and northwestern states, and in August to October in the southwestern region.

Adapted from: Annals of Allergy, Richard Weber, MD,

October 2001.