This matrix ecological system is composed of sagebrush dwarf-shrub-steppe that occurs in a variety of shallow-soil habitats throughout eastern Oregon, northern Nevada and southern Idaho. Artemisia arbuscula ssp. arbuscula and close relatives (Artemisia arbuscula ssp. longiloba and occasionally Artemisia nova) form stands that typically occur on mountain ridges and flanks and broad terraces, ranging from 1000 to 3000 m in elevation. Substrates are shallow, fine-textured soils, poorly drained clays, shallow-soiled areas, almost always very stony, characterized by recent rhyolite or basalt. Other shrubs and dwarf-shrubs present may include Purshia tridentata, Eriogonum spp., and other species of Artemisia. Common graminoids include Festuca idahoensis, Koeleria macrantha, Pseudoroegneria spicata, and Poa secunda. Many forbs also occur and may dominate the herbaceous vegetation, especially at the higher elevations. Isolated individuals of Juniperus occidentalis (western juniper) and Cercocarpus ledifolius (mountain-mahogany) can often be found in this system.
Information Source: http://www.natureserve.org/explorer/