Elymus elymoides

This plant is a common component of sagebrush (Artemisia spp.)/grass communities of the Intermountain shrubsteppe and is a common component of pinyon-juniper (Pinus spp.-Juniperus spp.) communities of the Great Basin, but it most commonly occurs in disturbed areas of deserts, valleys, foothills, and mountain meadows (Simonin, 2001). It can grow in a wide range of habitats, from shadscale communities to alpine tundra in a wide range of elevations from 4000 to 10,500 feet. Elymus elymoides ssp. elymoides is common at low to middle elevations in the western states. Subspecies californicus is native to mid-elevations up to alpine areas of Canada, California, Nevada and Utah. Subspecies brevifolius is found in a wide variety of habitats including desert and mountain plant communities, while subspecies hordeoides is restricted to the low lands of the Great Basin. Elymus multisetus occupies a similar range to ssp. elymoides, but is typically found in somewhat wetter, more mesic sites often in and near mountain foothills. In general, squirreltail is adapted to a wide range of ecological and topographical conditions. Plants can be found from 600 to 3,500 meters (2,000 to 11,500 feet) elevation in desert shrub to alpine plant communities. The different species-subspecies are adapted to sites receiving as little as 8 inches mean annual precipitation on upland sites or 5 to 9 inches in low lying areas that receive additional moisture. Big squirreltail is normally found in sites with 10 inches or more mean annual precipitation. Squirreltail grows well in medium to fine-textured soils, but also commonly occupies coarse-textured to gravelly soils. It tolerates low to moderately saline to alkaline run-in or overflow sites with electrical conductivity (EC) generally less than 10 (USDA NRCS, 2010). Bottlebrush squirreltail inhabits a wide variety of soil types and is tolerant of saline (Jensen et al., 1990) and alkaline soils. It is widely distributed in salt-desert shrub ranges of the west, on dry, gravelly soils, or within alkaline conditions. Bottlebrush squirreltail is found on clayey soils of northeastern California sagebrush communities (Simonin, 2001).

Bottlebrush squirreltail has the ability to produce large numbers of highly germinable seeds, with relatively rapid germination when exposed to the correct environmental cues. Seeds are readily dispersed by wind a few days following maturation. Dispersal is a function of bottlebrush squirreltail's long reflexed awns and disarticulating, mature inflorescence. Seeds are dispersed when the spike inflorescence is carried along the ground by wind catching the long awns. Although it has the potential for long distance seed dispersal, Martlette and Anderson (1986) found natural plant cover to act as a barrier to dispersal. Wind dispersal of bottlebrush squirreltail seed did not exceed 131 feet (40 m), with viable seed remaining relatively close to mature bottlebrush squirreltail plants. Dormancy protects bottlebrush squirreltail seeds from germinating during seasonal dry periods. Dry seeds require a period of afterippening, which widens environmental conditions conducive to germination. Germination rate increased and dormancy levels decreased as the duration of dry storage increased. Desert bottlebrush squirreltail seed commonly show higher levels of dormancy than seed from mountain populations. Bottlebrush squirreltail seeds may germinate without a period of afterippening, showing a partial state of dormancy. However mean germination time for recently harvested seeds is longer than for afterippened seeds (Simonin, 2001).