CEGL Artemisia tridentata ssp. Colloquial Name: No Data Available. Type Concept: This association is common and widespread throughout the sagebrush zone of the western Great Plains through southern British Columbia, south into the Great Basin, northern Colorado Plateau, and western Wyoming. Slopes may be gentle to steep, and aspect is not important in determining the distribution of this association.
Stands occupy moderately deep to deep loamy soils often with coarse fragments , sometimes with a cemented clay layer limiting water and root penetration.
Parent materials are variable. Throughout the geographic range of this type, Artemisia tridentata ssp. The shrubs Chrysothamnus spp. The herbaceous understory is generally a diverse mix of grasses and forbs. Pseudoroegneria spicata contributes more cover to the diverse herbaceous layer than does any other native species, and Achnatherum thurberianum, Festuca idahoensis, Hesperostipa comata, Poa secunda, Koeleria macrantha , and Poa fendleriana are often present.
Forbs are variable across the range of this type, but common species include Eriogonum umbellatum, Sphaeralcea coccinea , and Balsamorhiza sagittata. Stands in the eastern part of the geographic range often include Gutierrezia sarothrae, Artemisia frigida , and Bouteloua gracilis. The height of the sagebrush ranges from about 35 cm tall in the eastern part of the range to about 1 m tall in the western part. Diagnostic Characteristics: No Data Available. It may be preferable to first combine these two types, and then split them geographically.
The occurrences from the Great Plains west as far as northwestern Colorado, western Wyoming, and western Montana might belong to one type characterized by the presence of Bouteloua spp. The occurrences from southern Idaho, northern Nevada, eastern Oregon, eastern Washington, and British Columbia could belong to a different type characterized by the presence of Achnatherum thurberianum , and by the absence of the other species listed above. The separation between these two types probably would occur in Idaho.
