Physiognomy and Structure: This group is a facultatively deciduous, extremely xeromorphic, subdesert short shrubland with a typically open shrub canopy and sparse to moderately dense herbaceous layer dominated by perennial graminoids.

Floristics: This widespread cool semi-desert scrub group is highly variable and ranges from almost pure occurrences of a single species to fairly complex mixtures. The characteristic mix of low shrubs and grasses is sparse, with large open spaces between the plants (Blaisdell and Holmgren 1984). Occurrences have a sparse to moderately dense cover of woody species that is often dominated by one of several shrubs such as Atriplex canescens (also codominated by Artemisia tridentata, Ephedra viridis, or Krascheninnikovia lanata), Atriplex confertifolia (also codominated by several species of Lycium and Ephedra, Picrothamnus desertorum, or Sarcobatus vermiculatus), Atriplex cuneata, Atriplex obovata, Atriplex hymenelytra, Atriplex polycarpa, Grayia spinosa, or Picrothamnus desertorum (= Artemisia spinescens). Other shrubs may be present, especially in transition areas with desert or montane scrub. Species include Acacia greggii, Artemisia frigida, Chrysothamnus spp., Encelia frutescens, Ericameria nauseosa, Ephedra nevadensis, Frankenia salina, Larrea tridentata, Lycium andersonii, Lycium pallidum, Parthenium confertum, Psorothamnus polydenius, Purshia stansburiana, Suaeda spp., Tetradymia glabrata, Tetradymia spinosa, Tiquilia latior, and Yucca glauca. Dwarf-shrubs include Gutierrezia sarothrae and several species of Eriogonum, but generally do not form a distinct layer as the main shrub layer is often >0.5 m tall.

Warm-season medium-tall and short perennial grasses dominate in the sparse to moderately dense graminoid layer. The species present depend on the geographic range of the grasses, soil alkalinity/salinity, and past land use. Species may include Achnatherum hymenoides, Bouteloua gracilis, Distichlis spicata, Elymus elymoides, Hesperostipa comata, Leymus ambiguus, Leymus salinus, Muhlenbergia torreyi, Pascopyrum smithii, Pleuraphis jamesii, Poa secunda, Pseudoroegneria spicata, Sporobolus airoides, and Sporobolus cryptandrus. A number of annual species may also grow in association with the shrubs and grasses, although they are usually rare and confined to areas of recent disturbance (Blaisdell and Holmgren 1984). Forb cover is generally sparse. Perennial forbs that might occur include Chaetopappa ericoides, Descurainia spp., Mentzelia spp., Sphaeralcea coccinea, and Xylorhiza venusta. Annual natives include Monolepis nuttalliana, Plantago spp., or Vulpia octoflora. Associated halophytic annuals include Salicornia bigelovii, Salicornia rubra, and Suaeda species. Exotic annuals that may occur include Salsola kali, Bromus rubens, and Bromus tectorum. Cacti such as species of Opuntia and Echinocereus may be present in some occurrences. Trees are not usually present but some scattered Juniperus spp. may be found.

Dynamics:  West (1982) stated that "salt desert shrub vegetation occurs mostly in two kinds of situations that promote soil salinity, alkalinity, or both. These are either at the bottom of drainages in enclosed basins or where marine shales outcrop." However, salt-desert shrub vegetation may be an indication of climatically dry as well as physiologically dry soils (Blaisdell and Holmgren 1984). Not all salt-desert shrub soils are salty, and their hydrologic characteristics may often be responsible for the associated vegetation (Naphan 1966). Species of the salt-desert shrub complex have different degrees of tolerance to salinity and aridity, and they tend to sort themselves out along a moisture/salinity gradient (West 1982). Species and communities are apparently sorted out along physical, chemical, moisture, and topographic gradients through complex relations that are not understood and are in need of further study (Blaisdell and Holmgren 1984).

The winter months are a good time for soil moisture accumulation and storage within stands in this group. There is generally at least one good snowstorm per season that will provide sufficient moisture to the vegetation. The winter moisture accumulation amounts will affect spring plant growth. Plants may grow as little as a few inches to 1 m. Unless more rains come in the spring, the soil moisture will be depleted in a few weeks, growth will slow and ultimately cease, and the perennial plants will assume their various forms of dormancy (Blaisdell and Holmgren 1984). If effective rain comes later in the warm season, some of the species will renew their growth from the stage at which it had stopped. Others, having died back, will start over as if emerging from winter dormancy (Blaisdell and Holmgren 1984). Atriplex confertifolia shrubs often develop large leaves in the spring, which increase the rate of photosynthesis. As soil moisture decreases, the leaves are lost, and the plant takes on a dead appearance. During late fall, very small overwintering leaves appear which provide some photosynthetic capability through the remainder of the year. Other communities are maintained by intra- or inter-annual cycles of flooding followed by extended drought, which favor accumulation of transported salts. The moisture supporting these intermittently flooded wetlands is usually derived off-site, and they are dependent upon natural watershed function for persistence (Reid et al. 1999).

In summary, desert communities of perennial plants are dynamic and changing. The composition within this group may change dramatically and may be both cyclic and unidirectional. Superimposed on the compositional change is great variation from year to year in growth of all the vegetation, the sum of varying growth responses of individual species to specific conditions of different years (Blaisdell and Holmgren 1984). Desert plants grow when temperature is satisfactory, but only if soil moisture is available at the same time. Because the amount of moisture is variable from year to year and because different species flourish under different seasons of soil moisture, seldom do all components of the vegetation thrive in the same year (Blaisdell and Holmgren 1984).