General: Squirreltail is a cool-season C-3 bunchgrass native to the western United States. Foliage can be glabrous but is more often white hairy throughout. Plants are short, 10 to 45 cm (4 to 25 inches) tall, with culms erect to spreading. Leaf blades are flat to involute, 1 to 6 mm (0.04 to 0.24 inches) wide. The inflorescence is a spike from 2 to 17 cm (0.8 to 6.7 inches) long, not counting the awns. Internodes of the inflorescence are from 2 to 10 mm (0.08 to 0.40 inches) long with the rachis disarticulating regularly. At maturity the spike can be over 12 cm (4.7 inches) wide due to the widely spreading awns. Awns are scabrous and may grow from 2 to as much as 10 cm (0.8 to 3.9 inches) long, these often becoming purple with maturity.
Squirreltail is a self-pollinating allotetraploid and is known to hybridize with other species of Elymus as well as with members of Hordeum (barley) and Pseudoroegneria (bluebunch wheatgrass). Plants flower from late May to August.
Distribution: Squirreltail (in the broad sense) can be found throughout western North America from Canada to Mexico. For current distribution, please consult the Plant Profile page for this species on the PLANTS Web site.
Habitat: Bottlebrush and big squirreltail grow in a wide range of habitats, from shadscale communities to alpine tundra. 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.
Though bottlebrush and big squirreltail are commonly referred to as Sitanion hystrix (Nutt.) J.G. Smith and Sitanion jubatum J.G. Smith, respectively, squirreltail is becoming more widely accepted through cytological and molecular evidence as belonging to the genus Elymus.
The squirreltail complex, Elymus section Sitanion, is composed of two species, E. multisetus (J.G. Sm.) M.E. Jones (big squirreltail) and E. elymoides (Raf.) Swezey (bottlebrush squirreltail), with E. elymoides being further divided into four subspecies: elymoides, brevifolius (J.G. Sm.) Barkworth, californicus (J.G. Sm.) Barkworth, and hordeoides (Suksd.) Barkworth. The following key will be useful in separating the various members of section Sitanion including subspecies.
1. glumes 3- to many-cleft; auricles mostly
apparent, circa 1mm in length E. multisetus
1. glumes entire or 2-cleft; auricles mostly < 1mm
2. spikelets usually 2 per node
3. lowermost floret of one or both spikelets
at each node sterile and reduced to a
4. glumes 2-cleft; awns of glumes longer
than those of the lemmas
4. glumes entire; awns of lemma longer
than those of the glumes
3. lowermost floret fertile and not reduced
2. spikelets 3 per node, the floret of the central
spikelet fertile, those of the lateral spikelets
sterile and rudimentary ssp. hordeoides
For E. histrix: Elymus elymoides (Raf.) Swezey var. brevifolius (J.G. Sm.) Barkworth; Elymus elymoides (Raf.) Swezey ssp. californicus (J.G. Sm.) Barkworth; Elymuselymoides (Raf.) Swezey ssp. elymoides; Elymus elymoides (Raf.) Swezey ssp. hordeoides (Suksdorf) Barkworth; Sitanion hystrix (Nutt.) J.G. Smith; Elymus hystrix L. var. bigeloviana (Fern.) Bowden and Elymus hystrix L. var. histrix
For E. multisetus: Sitanion jubatum J.G. Sm.
Regularity: Regularly occurring
Regularity: Regularly occurring
Global Range: Squirreltail (in the broad sense) is widely distributed and can be found throughout western North America from British Columbia to Saskatchewan, south throughout the western and central United States to Mexico and from the west coast to the Dakotas and south to Oklahoma and Texas (Welsh et al., 1987; USDA NRCS, 2010).
Regional Distribution in the Western United States
This species can be found in the following regions of the western United States (according to the Bureau of Land Management classification of Physiographic Regions of the western United States):
BLM PHYSIOGRAPHIC REGIONS :
3 Southern Pacific Border
4 Sierra Mountains
5 Columbia Plateau
6 Upper Basin and Range
7 Lower Basin and Range
8 Northern Rocky Mountains
9 Middle Rocky Mountains
10 Wyoming Basin
11 Southern Rocky Mountains
12 Colorado Plateau
13 Rocky Mountain Piedmont
14 Great Plains
15 Black Hills Uplift
Occurrence in North America
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.
Reynolds and Fraley  found bottlebrush squirreltail roots to achieve depths of 39.4 inches (100 cm) below the soil surface. Depths below 39.4 inches (100 cm) were not seen due to a subsurface layer of basalt, suggesting rooting depths greater than 39.4 inches (100 cm) are possible. A lateral root extension of 16 inches (40 cm) was observed at 9.8, 20, 24 and 39.4 inch (25, 50, 60 and 100 cm) depths.
Palouse Grasslands Habitat
This taxon is found in the Palouse grasslands, among other North American ecoregions. The Palouse ecoregion extends over eastern Washington, northwestern Idaho and northeastern Oregon. Grasslands and savannas once covered extensive areas of the inter-mountain west, from southwest Canada into western Montana in the USA. Today, areas like the great Palouse prairie of eastern are virtually eliminated as natural areas due to conversion to rangeland. The Palouse, formerly a vast expanse of native wheatgrasses (Agropyron spp), Idaho Fescue (Festuca idahoensis), and other grasses, has been mostly plowed and converted to wheat fields or is covered by Drooping Brome (Bromus tectorum) and other alien plant species.
the Palouse historically resembled the mixed-grass vegetation of the Central grasslands, except for the absence of short grasses. Such species as Bluebunch Wheatgrass (Elymus spicatus), Idaho Fescue (Festuca idahoensis) and Giant Wildrye (Elymus condensatus) and the associated species Lassen County Bluegrass (Poa limosa), Crested Hairgrass (Koeleria pyramidata), Bottlebrush Squirrel-tail (Sitanion hystrix), Needle-and-thread (Stipa comata) and Western Wheatgrass (Agropyron smithii) historically dominated the Palouse prairie grassland.
Representative mammals found in the Palouse grasslands include the Yellow-bellied Marmot (Marmota flaviventris), found burrowing in grasslands or beneath rocky scree; American Black Bear (Ursus americanus); American Pika (Ochotona princeps); Coast Mole (Scapanus orarius), who consumes chiefly earthworms and insects; Golden-mantled Ground Squirrel (Spermophilus lateralis); Gray Wolf (Canis lupus); Great Basin Pocket Mouse (Perognathus parvus); Northern River Otter (Lontra canadensis); the Near Threatened Washington Ground Squirrel (Spermophilus washingtoni), a taxon who prefers habitat with dense grass cover and deep soils; and the Northern Flying Squirrel (Glaucomys sabrinus), a mammal that can be either arboreal or fossorial.
There are not a large number of amphibians in this ecoregion. The species present are the Great Basin Spadefoot Toad (Spea intermontana), a fossorial toad that sometimes filches the burrows of small mammals; Long-toed Salamander (Ambystoma macrodactylum); Northern Leopard Frog (Glaucomys sabrinus), typically found near permanent water bodies or marsh; Columbia Spotted Frog (Rana luteiventris), usually found near permanent lotic water; Pacific Treefrog (Pseudacris regilla), who deposits eggs on submerged plant stems or the bottom of water bodies; Tiger Salamander (Ambystoma tigrinum), fossorial species found in burrows or under rocks; Woodhouse's Toad (Anaxyrus woodhousii), found in arid grasslands with deep friable soils; Western Toad (Anaxyrus boreas), who uses woody debris or submerged vegetation to protect its egg-masses.
There are a limited number of reptiles found in the Palouse grasslands, namely only: the Northern Alligator Lizard (Elgaria coerulea), often found in screes, rock outcrops as well as riparian vicinity; the Painted Turtle (Chrysemys picta), who prefers lentic freshwater habitat with a thick mud layer; Yellow-bellied Racer (Chrysemys picta); Ringneck Snake (Diadophis punctatus), often found under loose stones in this ecoregion; Pygmy Short-horned Lizard (Phrynosoma douglasii), a fossorial taxon often found in bunchgrass habitats; Side-blotched Lizard (Uta stansburiana), frequently found in sandy washes with scattered rocks; Southern Alligator Lizard (Elgaria multicarinata), an essentially terrestrial species that prefers riparian areas and other moist habitats; Pacific Pond Turtle (Emys marmorata), a species that usually overwinters in upland habitat; Western Rattlesnake (Crotalus viridis), who, when inactive, may hide under rocks or in animal burrows; Night Snake (Hypsiglena torquata); Western Skink (Plestiodon skiltonianus), who prefers grasslands with rocky areas; Western Terrestrial Garter Snake (Thamnophis elegans), found in rocky grasslands, especially near water; Rubber Boa (Charina bottae).
Comments: 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 wide ecological amplitude , but it most commonly occurs in disturbed areas of deserts, valleys, foothills, and mountain meadows .
Bottlebrush squirreltail is found throughout Colorado on dry hills, plains, and rocky slopes, and within open woods and meadows . In Montana, bottlebrush squirreltail occurs in dry, open habitats, from valley to timberline . Throughout the western Great Plains, bottlebrush squirreltail is commonly found on dry soils of pastures and roadsides . In Utah, bottlebrush squirreltail prefers dry to moist vegetation types, from salt desert shrub to alpine grassland . Plains, rocky hills, or montane slopes are common sites in New Mexico . In Arizona, open sandy ground, rocky hills, and open pine woods are common sites . Bottlebrush squirreltail is common to dry rangeland areas of Kansas . In central Washington, bottlebrush squirreltail prefers disturbed sites. Within these sites plant density is negatively correlated with individual plant size . In California, bottlebrush squirreltail is found in scattered stands at high elevations on dry, gravelly soils. It is also common to hillsides and brush associations .
Bottlebrush squirreltail inhabits a wide variety of soil types and is tolerant of saline  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 . Throughout Montana it occurs predominantly on dry, gravelly soils, in saline or alkaline areas . Within alpine areas of Olympic National Park, Washington, bottlebrush squirreltail prefers well-drained, undifferentiated, disturbed, shallow and stony soils . Passey and Hugie  found bottlebrush squirreltail to achieve better growth on Newdale silt loam soils than on Brunt silt loam, in areas with similar climate, slope, and exposure. Bottlebrush squirreltail may also occur on loose, ashy soil .
Bottlebrush squirreltail is not common within wet areas such as river lowlands and soil along irrigation canals .
Elevation by state:
|Arizona||2,000 to 11,500 (609-3,505 m)  |
|west-central Montana||7,000 to 9,200 feet (2,135-2,805 m)  |
|New Mexico||4,500 to 11,500 feet (1,372-3,505 m) |
|Utah||3,510 to 11,400 feet (1,070-3,500 m) |
Key Plant Community Associations
Bottlebrush squirreltail is a common component of sagebrush (Artemisia spp.)/grass
communities of the Intermountain shrubsteppe [109,212].
Within rangelands of Utah, Nevada, southern Idaho, and western Wyoming, bottlebrush squirreltail
commonly grows under and adjacent to shadscale (Atriplex confertifolia), black greasewood
(Sarcobatus vermiculatus), and green rabbitbrush (Chrysothamnus viscidiflorus)
squirreltail is a common component of pinyon-juniper (Pinus spp.-Juniperus spp.)
communities of the Great Basin. It occurs mostly within the mountain ranges of Nevada and Utah,
and to a lesser extent in California and Idaho .
Bottlebrush squirreltail occurs in northern desert shrub communities  and
ponderosa pine (Pinus ponderosa) forests [39,137]. Within aspen (Populus tremuloides)-bunchgrass
communities of northern Arizona, bottlebrush squirreltail commonly occurs with
Arizona fescue (Festuca arizonica), mountain muhly (Muhlenbergia montana), western yarrow
(Achillea millefolium), lupine (Lupinus spp.), fleabane (Erigeron spp.) and
American vetch (Vicia americana) . Bottlebrush squirreltail is occasionally found
in openings and under shrub canopies within shrub live oak (Quercus turbinella)-mixed shrub
Bottlebrush squirreltail is native to California's central valley
and is commonly associated with purple tussock grass (Nassella
pulchra), nodding tussock grass (N. cernua), smallflower tussockgrass
(N. lepida), and shooting star (Dodecatheon
It is a minor component of blue oak (Quercus douglasii) [28,126] and interior live oak
(Q. wislizenii) habitats .
Within sagebrush scrub of the White Mountains, prairie Junegrass
(Koeleria macrantha), muhly (Muhlenbergia spp.) and timberline bluegrass (Poa
glauca spp. rupicola) are common associates . Within alluvial
fans of desert shrub communities, bottlebrush squirreltail is commonly associated
ricegrass (Achnatherum hymenoides)
and desert needlegrass (A. speciosum). Shrub associates of bottlebrush squirreltail
include California jointfir (Ephedra californica), goldenfleece (Ericameria arborescens),
white burrobrush (Hymenoclea salsola), and purple sage (Salvia dorrii) .
Bottlebrush squirreltail occasionally occurs in alpine flora of the Sierra Nevada eastern
slope . It is also an occasional understory species of California red fir (Abies magnifica)
forests in the Sierra Nevada .
Bottlebrush squirreltail is a member
of north-central Colorado's short-grass prairie [45,57,175]. Within the short-grass
prairie, bottlebrush squirreltail is commonly associated with western wheatgrass (Pascopyrum smithii),
purple threeawn (Aristida purpurea), sideoats grama (Bouteloua curtipendula),
blue grama (Bouteloua gracilis), buffalo grass (Buchloe dactyloides), and needle-and-thread
grass (Hesperostipa comata) . It occurs in blue grama ranges of Colorado
along with sun sedge (Carex heliophila), sand dropseed (Sporobolus cryptandrus),
and purple threeawn .
Within Colorado pinyon-Utah juniper (Pinus edulis-Juniperus osteosperma) habitats of Colorado, bottlebrush squirreltail
is associated with Gambel oak (Quercus gambelii), Utah serviceberry (Amelanchier utahensis),
true mountain-mahogany (Cercocarpus montanus), fendlerbush (Fendlera rupicola),
banana yucca (Yucca baccata), and antelope bitterbrush (Purshia tridentata). Grass
associates include cheatgrass (Bromus tectorum), Indian ricegrass, mutton grass
(Poa fendleriana), and brome grasses (Bromus spp.) .
Bottlebrush squirreltail is an occasional associate of Rocky Mountain bristlecone pine
(Pinus aristata) .
Bottlebrush squirreltail is a dominant species in shadscale communities of south-central
Idaho , along with Indian ricegrass .
Bottlebrush squirreltail generally occurs as scattered plants on rangelands .
In the eastern plains of Montana, bottlebrush squirreltail is a dominant species
of saline rangelands in association with alkali sacaton (Sporobolus airoides),
western wheatgrass (Pascopyrum smithii), thickspike wheatgrass (Elymus lanceolatus), inland saltgrass
(Distichlis stricta), Sandberg bluegrass (Poa secunda), and basin wildrye
(Leymus cinereus). Shrub associates include black greasewood and
Nuttall's saltbush (Atriplex nuttallii).
Bottlebrush squirreltail occurs
in gray low sagebrush (Artemisia arbuscula ssp. arbuscula) and big sagebrush (A. tridentata)
communities. Principal grass associates include cheatgrass , Sandberg bluegrass [24,25],
bluebunch wheatgrass (Pseudoroegneria spicata), and Thurber needlegrass (Achnatherum thurberianum).
Common shrub associates include green rabbitbrush and
gray horsebrush (Tetradymia canescens). Forb associates include bird's-beak
(Cordylanthus ramosus), mourning milkvetch (Astragalus atratus),
woollypod milkvetch (Astragalus purshii),
desert yellow fleabane (Erigeron linearis), lava aster (Lonactis alpina),
Heerman's buckwheat (Eriogonum heermanii), tail cup lupine (Lupinus caudatus)
and phlox (Phlox longifolia) .
In northeastern Nevada bottlebrush squirreltail is commonly found with black sagebrush
(Artemisia nova) [107,219], shadscale, Nevada ephedra (Ephedra nevadensis),
Sandberg bluegrass and Indian ricegrass .
also occurs in shadscale communities [24,145]. Common shrub associates include green molly
(Kochia americana), winterfat (Krascheninnikovia lanata), budsage
(Artemisia spinescens) and spiny hopsage (Grayia spinosa )
. Common grass associates are cheatgrass, Indian ricegrass
 and galleta (Pleuraphis jamesii) . Several common forb associates are
(Halogeton glomeratus), Adonis blazingstar (Mentzelia multiflora) and gooseberryleaf
globemallow (Sphaeralcea grossulariifolia). Bottlebrush squirreltail is also common to
juniper (Juniperus spp.) and greasewood communities .
Bottlebrush squirreltail is found in Wyoming big sagebrush (Artemisia tridentata ssp.
wyomingensis) rangelands of Nevada .
Eastern Oregon grass associates of bottlebrush squirreltail include bluebunch wheatgrass,
prairie Junegrass , Idaho fescue (Festuca idahoensis),
Thurber needlegrass [31,59], Sandberg bluegrass and
cheatgrass. Common forbs include Hood's phlox (Phlox hoodii) and
maiden blue eyed Mary (Collinsia parviflora) . Bottlebrush squirreltail
occurs in lodgepole pine stands in the
Cascades of Oregon , along with western needlegrass (Achnatherum occidentale)
and Ross' sedge (Carex rossii) .
In western Texas bottlebrush squirreltail occurs in Pinchot juniper (Juniperus pinchotii)
rangelands with sideoats grama, buffalo grass,
slim tridens (Tridens muticus), awnless bushsunflower (Simsia calva) and
plains fleabane (Erigeron modestus) .
Bottlebrush squirreltail is common in salt-desert shrub ranges along with the shrubs
shadscale (Atriplex confertifolia), mat saltbush (A. corrugata), fourwing
saltbush (A. canescens), valley saltbush (A. cunneata), greasewood,
winterfat, spiny hopsage, budsage, black sagebrush and
green rabbitbrush. Common grasses include Indian ricegrass,
Sandberg bluegrass, galleta,
alkali sacaton, sand dropseed, and
blue grama. Bottlebrush squirreltail is also
found in pinyon-juniper woodlands , ponderosa pine savannas  along with
dry Douglas-fir (Pseudotsuga menziesii) and mixed conifer habitats .
Bottlebrush squirreltail commonly occurs in big sagebrush steppe along with
aspen, big sagebrush, mountain snowberry (Symphoricarpos oreophilus),
Utah serviceberry, rose (Rosa spp.),
Scouler's willow (Salix scouleriana),
and Oregon-grape (Mahonia repens). Common forb associates include
rosy pussytoes (Antennaria microphylla), arrowleaf buckwheat
(Eriogonum compositum), pineywoods geranium (Geranium caespitosum) and
northern bedstraw (Galium boreale). Graminoid associates include needle-and-thread grass,
Columbia needlegrass (Achnatherum nelsonii), and elk sedge (Carex geyeri) .
Classifications describing plant communities in which bottlebrush squirreltail is a dominant species are as
New Mexico [94,146]
Habitat: Rangeland Cover Types
This species is known to occur in association with the following Rangeland Cover Types (as classified by the Society for Range Management, SRM):
More info for the terms: association, cover, shrub
SRM (RANGELAND) COVER TYPES :
101 Bluebunch wheatgrass
102 Idaho fescue
104 Antelope bitterbrush-bluebunch wheatgrass
105 Antelope bitterbrush-Idaho fescue
106 Bluegrass scabland
107 Western juniper/big sagebrush/bluebunch wheatgrass
108 Alpine Idaho fescue
109 Ponderosa pine shrubland
110 Ponderosa pine-grassland
201 Blue oak woodland
207 Scrub oak mixed chaparral
211 Creosotebush scrub
301 Bluebunch wheatgrass-blue grama
310 Needle-and-thread-blue grama
314 Big sagebrush-bluebunch wheatgrass
315 Big sagebrush-Idaho fescue
318 Bitterbrush-Idaho fescue
320 Black sagebrush-bluebunch wheatgrass
321 Black sagebrush-Idaho fescue
322 Curlleaf mountain-mahogany-bluebunch wheatgrass
401 Basin big sagebrush
403 Wyoming big sagebrush
405 Black sagebrush
406 Low sagebrush
407 Stiff sagebrush
408 Other sagebrush types
409 Tall forb
410 Alpine rangeland
412 Juniper-pinyon woodland
413 Gambel oak
414 Salt desert shrub
415 Curlleaf mountain-mahogany
416 True mountain-mahogany
417 Littleleaf mountain-mahogany
503 Arizona chaparral
504 Juniper-pinyon pine woodland
509 Transition between oak-juniper woodland and mahogany-oak association
611 Blue grama-buffalo grass
614 Crested wheatgrass
704 Blue grama-western wheatgrass
712 Galleta-alkali sacaton
715 Grama-buffalo grass
727 Mesquite-buffalo grass
735 Sideoats grama-sumac-juniper
Habitat: Cover Types
This species is known to occur in association with the following cover types (as classified by the Society of American Foresters):
More info for the term: cover
SAF COVER TYPES :
66 Ashe juniper-redberry (Pinchot) juniper
207 Red fir
209 Bristlecone pine
210 Interior Douglas-fir
218 Lodgepole pine
220 Rocky Mountain juniper
229 Pacific Douglas-fir
237 Interior ponderosa pine
238 Western juniper
241 Western live oak
243 Sierra Nevada mixed conifer
244 Pacific ponderosa pine-Douglas-fir
246 California black oak
250 Blue oak-foothills pine
256 California mixed subalpine
Habitat: Plant Associations
This species is known to occur in association with the following plant community types (as classified by Küchler 1964):
More info for the term: shrub
KUCHLER  PLANT ASSOCIATIONS:
K005 Mixed conifer forest
K007 Red fir forest
K008 Lodgepole pine-subalpine forest
K010 Ponderosa shrub forest
K011 Western ponderosa forest
K012 Douglas-fir forest
K016 Eastern ponderosa forest
K017 Black Hills pine forest
K018 Pine-Douglas-fir forest
K019 Arizona pine forest
K020 Spruce-fir-Douglas-fir forest
K021 Southwestern spruce-fir forest
K022 Great Basin pine forest
K023 Juniper-pinyon woodland
K024 Juniper steppe woodland
K026 Oregon oakwoods
K030 California oakwoods
K031 Oak-juniper woodland
K032 Transition between K031 and K037
K037 Mountain-mahogany-oak scrub
K038 Great Basin sagebrush
K046 Desert: vegetation largely lacking
K052 Alpine meadows and barren
K053 Grama-galleta steppe
K054 Grama-tobosa prairie
K055 Sagebrush steppe
K056 Wheatgrass-needlegrass shrubsteppe
K057 Galleta-threeawn shrubsteppe
K059 Trans-Pecos shrub savanna
K060 Mesquite savanna
K065 Grama-buffalo grass
K085 Mesquite-buffalo grass
K086 Juniper-oak savanna
This species is known to occur in the following ecosystem types (as named by the U.S. Forest Service in their Forest and Range Ecosystem [FRES] Type classification):
FRES21 Ponderosa pine
FRES26 Lodgepole pine
FRES28 Western hardwoods
FRES30 Desert shrub
FRES32 Texas savanna
FRES33 Southwestern shrubsteppe
FRES34 Chaparral-mountain shrub
FRES36 Mountain grasslands
FRES38 Plains grasslands
FRES40 Desert grasslands
For best results, seed should be planted to a depth of ¼ to ½ inches into a firm weed-free seedbed. For pure stands the recommended drill seeding rate is 7 lb pure live seed (PLS) per acre. Seed can be planted in early spring, but late dormant fall seeding is recommended for best annual weed suppression.
Squirreltail does not establish well into existing perennial shrub communities without mechanical treatment to reduce shrub density. Studies show four times the establishment success rate of squirreltail when planted after thinning big sagebrush (Artemisia tridentata Nuttall) as opposed to an untreated site. Similarly, it has been difficult to establish squirreltail in stands of crested wheatgrass (Agropyron cristatum [L.] Gaertner). It is recommended that crested wheatgrass and other perennial species competition be eliminated or severely reduced prior to seeding native seed mixtures that include squirreltail.
Based on studies in:
USA: California, Cabrillo Point (Grassland)
This list may not be complete but is based on published studies.
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: > 300
Comments: Elymus elymoides ssp. brevifolius occurs in the San Bernardino Mountains, Peninsular Ranges, Modoc Plateau, and Mojave Desert of California to Oregon, the Great Plains and south to northern Mexico. Elymus elymoides ssp. californicus is found in the Klamath Range, Cascade Range, Sierra Nevada, San Gabriel Mountains, San Bernardino Mountains, east Sierra Nevada of California to Washington, Montana and Utah. Elymus elymoides ssp. elymoides is found in the Transverse Ranges, San Jacinto Mountains, and Great Basin floristic Province from California to Washington, Wyoming and Colorado. Elymus elymoides ssp. hordeoides occurs in Klamath Range from California to Washington and Nevada (Welsh et al., 1987). It barely ranges into western North Dakota, cited by Stevens (1963) (as Sitanion hystrix) from Medora in 1940 and Bismarck in 1946.
Fire Management Considerations
Humphrey and Schupp  compared bottlebrush squirreltail seedling emergence within burned and unburned cheatgrass dominated areas of the Great Basin, Utah. Greater seedling emergence (April) occurred on seeded burned areas compared to unseeded, within loamy fine sand (85% sand) sites. On a dune site with sandy soil (95% sand), seedling emergence occurred in March with no significant difference between burned and unburned sites. However, a significantly greater proportion of bottlebrush squirreltail seedlings survived on burned dune areas compared to unburned.
Aerially applied seed mixture of mutton grass, prairie Junegrass, Indian ricegrass, slender wheatgrass (Elymus trachycaulus) and bottlebrush squirreltail aided in the reestablishment of bottlebrush squirreltail after a summer (August) wildfire within Mesa Verde National Park, Colorado . Bottlebrush squirreltail was an important component 1, 2,  and 3 postfire years  in seeded areas, whereas no bottlebrush squirreltail was observed in unseeded areas .
Postfire recovery of bottlebrush squirreltail occurred after a summer (June 1956) wildfire in Arizona chaparral, aerially seeded with weeping lovegrass (Eragrostis curvula) and crested wheatgrass. Results shown that percent frequency of bottlebrush squirreltail within 9.6 foot (2.9 m) square plots increased steadily for 4 years postfire :
Seeding postfire pinyon-juniper communities of the Great Basin with desert wheatgrass (Agropyron desertorum), intermediate wheatgrass (Thinopyrum intermedium), and smooth brome (Bromus inermis) inhibits establishment of bottlebrush squirreltail .
Four years after a late summer (July-August) wildfire in pinyon-juniper woodlands of Mesa Verde, Colorado, Erdman  found bottlebrush squirreltail as an important component. Bottlebrush squirreltail, along with Indian rice grass and mutton grass, assumed dominance after a 3-year annual grass/forb stage. At 25 postfire years, bottlebrush squirreltail is a member of climax stands.
Within pinyon-juniper ranges of west-central Utah, bottlebrush squirreltail is an important native perennial species at 5 to 6 postfire years .
A fire return interval less than 10 to 25 years should increase abundance of bottlebrush squirreltail in newly expanded (young) western juniper stands (Juniperus occidentalis) receiving greater than 14 inches (350 mm) precipitation, at elevations higher than 4,900 feet (1,500 m), in southwestern Idaho .
Broad-scale Impacts of Plant Response to Fire
Wright  compared bottlebrush squirreltail response to burning and
clipping near Boise, Idaho. Heat was applied by propane burner for 20 to 30 seconds to raise soil
surface temperature to 400 or 800 degrees Fahrenheit. The 800 degree Fahrenheit treatment killed 25%
of bottlebrush squirreltail plants during July and August. No other treatment caused mortality.
Burning and clipping during all seasons reduced yields 1 year after treatment. Burning reduced
yield most during May. Average herbage weight (in grams) per bottlebrush squirreltail plants
in relation to season and treatment at 1 postfire year is summarized below:
|Season||400 Â°F||800 Â°F||Clipped||Control|
a Differences from clipped treatment significant at p<0.05
b Differences from 400 Â°F treatment significant at p<0.05
Wright  conducted time/temperature evaluations of bottlebrush squirreltail mortality
on 5 dates between 19 May and 21 September, at temperatures between 120 to 200 degrees Fahrenheit
(48.9-93.3 Â°C). Time
required to kill bottlebrush squirreltail tissue at all temperatures within the test range increased
as burning date increased. The greatest change occurred between 10 June and 21 July.
Time (minutes) required to kill bottlebrush squirreltail tissue at 172 degrees Fahrenheit
(78 Â°C) :
|19 May||10 June||21 July||20 August||21 September|
Fox  found a direct association between postfire response of bottlebrush squirreltail and ponderosa pine
tree density and canopy cover. The greatest cover (%)
of bottlebrush squirreltail was achieved in areas with larger (>4 inches (10 cm) diameter) trees and
less dense tree canopies.
Blank and others  grew bottlebrush squirreltail under greenhouse conditions in soil
from a July wildfire site and adjacent unburned areas within a big sagebrush habitat of Nevada.
Bottlebrush squirreltail had greater aboveground biomass and more total N, P and K, along with greater silica
content, when grown in soil collected from wildfire sites.
Early spring fire (May) within sagebrush ecosystems of eastern Oregon greatly reduced
bottlebrush squirreltail basal area [31,32]. Basal area decreased an average of 47 %
the 2nd postfire year.
Britton and others  compared bottlebrush squirreltail postfire response in eastern
Oregon to clipping. Yield (1 postfire year) after a May fire was less than yield from clipping
(down to 0.4 inch (1 cm) stubble). Results the 2nd year showed no significant
Bottlebrush squirreltail populations increased after a "moderate" spring
(May 1972) wildfire in a ponderosa pine forest on limestone-sandstone derived soils, near flagstaff Arizona.
The area observed was logged 2 years before, averaging 16,875 board feet/acre (6,750 board feet/ha).
Number of bottlebrush
squirreltail stems per hectare in 1972 and 1974 is summarized below in thousands/ha :
|Moderate burn 1972||Severe burn 1972||Control (logged, not burned) 1972|
|Moderate burn 1974||Severe burn 1974||Control (logged, not burned) 1974|
Although frequency of bottlebrush squirreltail was too low for statistical analysis,
Champlin  reported no damage to bottlebrush squirreltail basal cover and height 2 postfire years after a
spring fire in a big sagebrush community of northern California. Bottlebrush squirreltail vigor increased the
1st and 2nd postfire growing season in central Oregon, following a spring fire within
a sagebrush-bitterbrush/bunchgrass plant community .
Bottlebrush squirreltail increased following an August wildfire in a big sagebrush
community with an understory dominated by cheatgrass and Lyall's milkvetch (Astragalus
lyallii) . Significantly (p<0.01) greater biomass was achieved 1 postfire
year after a 19 July prescribed fire in Oregon. At time of burn, bottlebrush
squirreltail had entered summer quiescence with no green shoot material evident. Mean
shoot biomass of burned plants was greater per unit crown area, compared to
control. Burned plants also averaged 49% higher root
biomass per unit crown area, producing a shoot:root biomass ratio of 1.73 compared to
control plots at 0.43 shoot:root biomass. Burning also increased the proportion of reproductive
culms; 74.8% of all shoots of burned plants produced reproductive culms compared to 14.3% for unburned plants
Bottlebrush squirreltail showed a negative postfire response to summer (July) wildfire
within a sagebrush rangeland in Utah, for the 2nd and 3rd postfire years compared to
Bottlebrush squirreltail decreased in abundance 1 postfire year after a summer
(July) prescribed fire and after a lightning fire within a mountain mahogany-big sagebrush community .
Bottlebrush squirreltail maintained previous levels of production (kg/ha) 1 postfire
year after an October fire in an aspen-bunchgrass community of northern Arizona.
Although total vegetative production remained constant, percent cover and density
of bottlebrush squirreltail were significantly higher. The October fire resulted in a
large bottlebrush squirreltail population consisting of small individuals whose
combined vegetative biomass equaled or exceeded preburn levels. Associated
dominants, Arizona fescue and mountain muhly, decreased .
For further information on bottlebrush squirreltail response to fire, see Fire Case Studies,
Lyon's Research Paper (Lyon 1971),
and the following Research Project Summaries:
Response of vegetation to prescribed burning in a Jeffrey pine-California
black oak woodland and a deergrass meadow at Cuyamaca State Park, California
Effects of fall and spring prescribed burning in sagebrush steppe in east-central Oregon
Vegetation response to restoration treatments in ponderosa pine-Douglas-fir forests of western Montana
Plant Response to Fire
Bottlebrush squirreltail sprouts from surviving root crown [29,201] and colonizes from seed .
Seasonal trends in bottlebrush squirreltail root carbohydrate reserves greatly affect postfire response. Burning is generally harmful during late spring and early summer [30,208] coinciding with low points in carbohydrate reserves . Bottlebrush squirreltail is most tolerant of late summer (anthesis) or mid-fall (before regrowth) fires [30,49,79], coinciding with relatively high carbohydrate reserves :
A difference in phenological traits of surviving postfire individuals may exist between small (1 to 3 inch (2.5-7.6 cm) crown diameter) and large (>3.5 inches (8.9 cm) crown diameter) bottlebrush squirreltail plants. Wright  found large plants to produce significantly (p<0.01) higher numbers of flowering stalks than small plants after fire.
Immediate Effect of Fire
Although bottlebrush squirreltail is generally top-killed by fire, its small size and low density of coarse fuel per unit basal area make it relatively fire tolerant [31,198,208]. Low density of above ground plant tissue produces a quick, "hot" flame, transferring little heat to growing points below the soil surface [208,210]. The solid culms of bottlebrush squirreltail do not readily burn, compared to those of perennial grass associates .
POSTFIRE REGENERATION STRATEGY :
Crown residual colonizer (on-site, initial community)
Secondary colonizer (on-site or off-site seed sources)
Bottlebrush squirreltail's small size, coarse stems, and sparse leafy material aid in its tolerance of fire . Postfire regeneration occurs from surviving root crowns and from on- and off-site seed sources . Frequency of disturbance greatly influences postfire response of bottlebrush squirreltail. Undisturbed plants within a 6 to 9 year age class generally contain large amounts of dead material, increasing bottlebrush squirreltail's susceptibility to fire .
Koniak  found bottlebrush squirreltail to be a major component of postfire pinyon-juniper communities of the Great Basin at any time during succession. Greatest occurrence and coverage of bottlebrush squirreltail are generally achieved during mid-seral stages.
|Successional stage||Occurrence (%)||Percent of areas achieving > 5% cover|
|Early (1 year old)||43||3|
|Early-mid (4-8 years old)||58||15|
|Mid (15-17 years old)||49||28|
|Late-mid (22-60 years old)||90||0|
|Late > 60 years old||44||0|
FIRE REGIMES for plant communities in which bottlebrush squirreltail occurs are summarized below. For further information regarding FIRE REGIMES and fire ecology of communities and ecosystems where bottlebrush squirreltail is found see "The Fire Ecology and Adaptations" section of the FEIS species summary for the plant community or ecosystem dominants listed below.
|Community or Ecosystem||Dominant Species||Fire Return Interval Range (years)|
|silver fir-Douglas-fir||Abies amabilis-Pseudotsuga menziesii var. menziesii||> 200|
|sagebrush steppe||Artemisia tridentata/Pseudoroegneria spicata||20-70 |
|basin big sagebrush||A. t. var. tridentata||12-43 |
|mountain big sagebrush||A. t. var. vaseyana||20-60 [7,37]|
|Wyoming big sagebrush||A. t. var. wyomingensis||10-70 (40)** [196,215]|
|saltbush-greasewood||Atriplex confertifolia-Sarcobatus vermiculatus|
|desert grasslands||Bouteloua eriopoda and/or Pleuraphis mutica||5-100|
|plains grasslands||Bouteloua spp.|
|blue grama-needle-and-thread grass-western wheatgrass||B. g.-Hesperostipa comata-Pascopyrum smithii|
|blue grama-buffalo grass||B. g.-Buchloe dactyloides|
|grama-galleta steppe||B. g.-Pleuraphis jamesii|
|blue grama-tobosa prairie||B. g.-P. mutica|
|cheatgrass||Bromus tectorum||mountain-mahogany-Gambel oak scrub||Cercocarpus ledifolius-Quercus gambelii|
|western juniper||Juniperus occidentalis||20-70|
|Rocky Mountain juniper||J. scopulorum|
|Sierra lodgepole pine*||Pinus contorta var. murrayana||35-200|
|Rocky Mountain ponderosa pine*||P. ponderosa var. scopulorum||2-10|
|Arizona pine||P. p. var. arizonica||2-10|
|galleta-threeawn shrubsteppe||Pleuraphis jamesii-Aristida purpurea|
|mesquite-buffalo grass||Prosopis glandulosa-Buchloe dactyloides|
|Texas savanna||P. g. var. glandulosa||33]|
|mountain grasslands||Pseudoroegneria spicata||3-40 (10)** |
|Rocky Mountain Douglas-fir*||Pseudotsuga menziesii var. glauca||25-100|
|interior live oak||Quercus wislizenii||33]|
More info for the terms: climax, shrub
Depending upon habitat type, bottlebrush squirreltail may occur as an early, mid-, or late successional species.
Bottlebrush squirreltail is generally a dominant component of seral big sagebrush/bunchgrass communities . Bottlebrush squirreltail is represented in early seral and climax stages of big sagebrush/bluebunch wheatgrass associations in Nevada. Tueller and Platou observed the most pronounced bottlebrush squirreltail during early and climax stages of big sagebrush/bluebunch wheatgrass associations in Nevada . Bottlebrush squirreltail is found within seral and climax stages of big sagebrush rangelands in southeastern Idaho . It is a component of climax big sagebrush communities in Idaho  and is a member of climax big sagebrush/western wheatgrass communities of Colorado . Within shrub-steppe ecosystems of western Colorado, bottlebrush squirreltail is an early seral species . Bottlebrush squirreltail also occurs in climax shadscale communities .
Bottlebrush squirreltail is common in mid-seral and climax pinyon-juniper communities of Mesa Verde, Colorado [67,68]. Bottlebrush squirreltail is a component of seral and climax western juniper (Juniper occidentalis) communities of the Pacific Northwest .
Ponderosa pine communities:
Bottlebrush squirreltail is a member of interior ponderosa pine climax communities within the central and southern Rocky Mountains .
Prior to invasion of nonnative annuals in the Snake River Plain, Idaho, bottlebrush squirreltail occupied a mid to late seral status, suppressing the early seral fescues, sixweeks fescue (Vulpia octoflora), and foxtail fescue (Vulpia myuros) .
Bottlebrush squirreltail regenerates from surviving root crown [29,201] and seed . Vegetative propagation is nonexistent . Bottlebrush squirreltail has the ability to produce large numbers [99,214] of highly germinable seeds, with relatively rapid germination  when exposed to the correct environmental cues. Plants are self-fertilizing . Seeds are readily dispersed by wind [15,99] a few days following maturation . Dispersal is a function of bottlebrush squirreltail's long reflexed awns and disarticulating, mature inflorescence [99,131,148]. Seeds are dispersed when the spike inflorescence is carried along the ground by wind catching the long awns .
Although bottlebrush squirreltail has the potential for long distance seed dispersal, Martlette and Anderson  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 . Allen and others  found 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.
Beckstead  evaluated the germination temperature requirements of recently harvested bottlebrush squirreltail seeds obtained from mountain and desert habitats. The greatest germination occurred primarily at 50/68 degrees Fahrenheit (10/20 °C) and 59/77 degrees Fahrenheit (15/25 °C), with higher temperatures of 68/86 degrees Fahrenheit (20/30 °C) inhibiting germination.
Environmental conditions and timing of phenological events greatly affect the probability of recently harvested bottlebrush squirreltail seed germination. Temperatures of 50/68 degrees Fahrenheit (10/20 °C) and 59/77 degrees Fahrenheit (15/25 °C) are unlikely to occur during summer months in desert habitats. In higher, mountain habitats, summer temperatures of 50/68 degrees Fahrenheit (10/20 °C) and 59/77 degrees Fahrenheit (15/25 °C) may occur; however, bottlebrush squirreltail usually ripens later at higher elevations . In general, recently harvested bottlebrush squirreltail seeds at lower elevations have a much greater probability of fall germination than seeds from higher elevations .
Chabet and Billings  observed germination of bottlebrush squirreltail seeds from alpine sites (10,793 feet (3,290 m)) in the Sierra Nevada. The greatest germination (%) occurred at day/night temperatures of 81/73 degrees Fahrenheit (27/23 °C (96%)) and 90/82 degrees Fahrenheit (32/28 °C (92%)).
Growth Form (according to Raunkiær Life-form classification)
More info for the term: hemicryptophyte
RAUNKIAER  LIFE FORM:
Life History and Behavior
More info for the term: phenology
The wide ecological amplitude of bottlebrush squirreltail leads to differential timing of phenological events between individuals of differing habitats [43,109]. Flowering generally occurs in spring or early summer [18,57]. Lower elevation populations (that is, cold desert, salt desert habitats) usually mature early June with higher elevation populations (that is, mountain brush, mountain meadows) reaching maturity in late July . Hironaka and Tisdale observed phenological differences between the subspecies Elymus elymoides ssp. elymoides and ssp. californicum. In a common garden experiment E. e. ssp. elymoides developed 10 to 14 days earlier than ssp. californicum .
Between 1960 and 1969, Murray and others evaluated bottlebrush squirreltail phenology in southern Idaho. Growth began from mid-March to mid-April. Flower stalks began to form late-April to mid-May, with anthesis occurring in early to mid-June. Plants were dormant from the middle of July to the end of August with fall regrowth occurring through October .
Clary  evaluated bottlebrush squirreltail phenology and rate of growth from different environments using a transplant garden and growth chamber. The timing of bottlebrush squirreltail phenological events and overall growth rate was closely related to homesite environmental conditions. Bottlebrush squirreltail individuals from higher elevations were limited by cold temperatures whereas individuals from lower elevations were limited by water availability and warm temperatures. Under the same environmental constraints, bottlebrush squirreltail from areas with low moisture stress and cool climates showed higher growth rates, attaining maximum height earlier than individuals from warmer drier sites. Bottlebrush squirreltail requires the longest time to flower in areas of relatively moderate temperature and moisture regimes:
Time to flowering in days for bottlebrush squirreltail individuals from different habitats is shown below. Plants were grown at 6,490 feet (1,980 m) on a clay loam with an annual precipitation of 21.4 inches (544 mm) and annual temperature of 49 degree Fahrenheit (9.5 oC).
|Bottlebrush squirreltail collection site description||Days to flower|
|7,410 feet (2,260 m), silt loam, ponderosa pine||205.5|
|4,990 feet (1,520 m), stony clay loam, ponderosa pine||201.2|
|7,200 feet (2,200 m), loam, pinyon-juniper||193.8|
|7,810 feet (2,380 m), clay loam, ponderosa pine||192.5|
|9,780 feet (2,980 m), gravelly loam, spruce-fir||172.5|
|9,320 feet (2,840 m), gravelly sandy loam, mountain grassland||166.8|
|4,530 feet (1,380 m), loamy fine sand, short grass||165.8|
|4,720 feet (1,440 m), cobble clay, pinyon-juniper||162.2|
|4,990 feet (1,520 m), stony clay loam, ponderosa pine||159.5|
|5,510 feet (1,680 m), silty clay loam, sagebrush-greasewood||158.0|
|4,530 feet (1,380 m), stony loam, oak savannah||153.5|
Bottlebrush squirreltail is responsive to fall rains in northern areas of the Great Basin, allowing for fall regrowth. Fall regrowth uses the majority of total available root carbohydrates partitioned during the summer . The optimal soil temperature for root and shoot growth occurs at approximately 77 degrees Fahrenheit (25 °C). However, bottlebrush squirreltail shows continuous root growth down to 41 degrees Fahrenheit (5 °C) soil temperature .
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).
Molecular Biology and Genetics
Statistics of barcoding coverage: Elymus elymoides
Public Records: 1
Specimens with Barcodes: 1
Species With Barcodes: 1
National NatureServe Conservation Status
Rounded National Status Rank: N4 - Apparently Secure
Rounded National Status Rank: N4 - Apparently Secure
NatureServe Conservation Status
Rounded Global Status Rank: G5 - Secure
Reasons: Squirreltail (in the broad sense) can be found throughout western North America from Canada to Mexico and is adapted to a wide range of ecological and topographical conditions. It is considered secure throughout its range and may even become weedy or invasive in some regions displacing desirable vegetation unless properly managed.
Environmental Specificity: Broad. Generalist or community with all key requirements common.
Comments: This species is tolerant to disturbance (Maser and Strickler, 1978). Its ability to germinate in the late fall and very early spring at a wide range of temperatures add to its capability to compete with cheatgrass (Bromus tectorum L.). Studies also indicate that squirreltail is capable of establishing in medusahead wildrye (Taeniatherum caput-medusae (L.) Nevski) infested sites. This makes squirreltail one of the more competitive native grasses available for reseeding disturbed rangelands. It is also a self-fertilizing species which allows it to produce seed despite sparse stands following seeding. Squirreltail is considered to be one of the most fire resistant native bunchgrasses. Older plants contain relatively low amounts of dead material when compared with other native bunchgrasses. This allows for hot, but quick burns which do not penetrate and damage the crown. However, during dry years plants can be damaged by severe burns. As an early-seral species, new plants often increase for two to three years following burns (USDA NRCS, 2010). 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).
Please consult the PLANTS Web site and your State Department of Natural Resources for this plant’s current status (e.g. threatened or endangered species, state noxious status, and wetland indicator values).
Global Short Term Trend: Relatively stable (=10% change)
Comments: It is considered secure throughout its range and may even become weedy or invasive in some regions displacing desirable vegetation unless properly managed (USDA NRCS, 2010).
Global Long Term Trend: Increase of 10-25% to decline of 30%
Degree of Threat: Unknown
Comments: Although bottlebrush squirreltail is generally top-killed by fire, its small size and low density of coarse fuel per unit basal area make it relatively fire tolerant (Britton et al., 1990; Wright, 1971). Low density of above ground plant tissue produces a quick, "hot" flame, transferring little heat to growing points below the soil surface (Wright, 1971; Wright and Klemmedson, 1965). The solid culms of bottlebrush squirreltail do not readily burn, compared to those of perennial grass associates (Wright and Klemmedson, 1965). Bottlebrush squirreltail's small size, coarse stems, and sparse leafy material aid in its tolerance of fire (Britton et al., 1990) Frequency of disturbance greatly influences postfire response of bottlebrush squirreltail. Undisturbed plants within a 6 to 9 year age class generally contain large amounts of dead material, increasing bottlebrush squirreltail's susceptibility to fire (Wright and Klemmedson, 1965). Koniak (1985) found bottlebrush squirreltail to be a major component of postfire pinyon-juniper communities of the Great Basin at any time during succession (Simonin, 2001).
Pests and potential problems
Plants are known to be susceptible to rust.
More info for the terms: competition, cover, culm, relict, succession, wildfire
The addition of nitrogen to disturbed sagebrush communities in Colorado  and mountain meadows of Nevada 
had no positive effect on
bottlebrush squirreltail establishment.
Bottlebrush squirreltail decreased after the addition of nutrients in the form of stabilized sewage
Bottlebrush squirreltail reproductive potential is adversely affected by jointworm larvae.
Spears and Barr 
found culm length, seed weight, germination (%),
and germination rate all significantly lower (p<0.01) on bottlebrush squirreltail
infested with jointworms compared to noninfested plants. Results are summarized below
|Culm length (cm)||30.0||33.7|
|Leaf length (cm)||22.0||23.1|
|# of spikelets||5||9|
|Seed weight (mg 25 seeds)||108.2||162.5|
|Growth rate (Seedlings day -1 100 seeds -1)||2.8||7.8|
Bottlebrush squirreltail is a valuable winter range plant in the Great Basin , with
leaves remaining green and succulent through the winter.
Bottlebrush squirreltail's total available root carbohydrate reserves are lowest in early spring
(approximately 3rd leaf stage), and at the beginning of fall regrowth. Total available carbohydrates are highest after
By the 4th leaf stage, bottlebrush squirreltail has replaced the carbohydrate
reserves found in roots at the beginning of the growing season . Wright 
found bottlebrush squirreltail most tolerant to herbage removal at
time of seed maturity, declining slightly after maturity before fall regrowth.
In eastern Oregon, bottlebrush squirreltail is resistant to late season defoliation 
Bottlebrush squirreltail generally increases in abundance when moderately grazed
or protected on the foothills of intermountain winter ranges .
Moderate trampling by livestock in big sagebrush rangelands of central Nevada enhanced
bottlebrush squirreltail seedling emergence compared to untrampled conditions. Heavy trampling
destroys germination sites and significantly
(p<0.05) reduces germination, whereas moderate trampling may
enhance germination .
Bottlebrush squirreltail is tolerant of grazing in big sagebrush rangelands of
southeastern Idaho .
In sagebrush rangelands of western Utah, Cook and Child  found winter harvesting
to have a minor effect on crown cover, whereas early spring (April 1, May 1) harvest greatly
reduced bottlebrush squirreltail cover.
Bottlebrush squirreltail vegetative vigor was evaluated over 25 years within a sagebrush rangeland
of southeastern Oregon excluded from grazing. Vigor of bottlebrush squirreltail increased
significantly over the 25 year period, with the 1st decade showing slower growth than the
2nd. The average annual precipitation over the 25 years equaled 8.3 inches (210 mm) with 40%
falling during April, May, and June. Winters were cold with snow cover from December to March.
Summers were hot, occasionally exceeding 100 degrees Fahrenheit (38 °C) .
Bottlebrush squirreltail is commonly found in heavily grazed and browsed
(cattle and deer) aspen stands of big sagebrush steppe in Wyoming .
McPherson and Wright  observed significantly (p<0.01) greater coverage of bottlebrush
squirreltail on ungrazed versus grazed Pinchot juniper rangelands in western Texas.
Within the ponderosa pine bunchgrass ranges of the central Rocky Mountains, bottlebrush squirreltail
production is greatest under light and moderate grazing regimes .
Bottlebrush squirreltail is tolerant of heavy grazing in the ponderosa pine zone of the Coconino Plateau, Arizona, since its long, sharp
awns are usually present to discourage grazing .
On shortgrass ranges of the central plains bottlebrush squirreltail is very tolerant of light
to moderate grazing .
Climax western juniper stands are of mixed age, consisting of 1st year seedlings to trees
several hundred years old. Seral stands are composed of predominately younger aged trees.
Oregon, Vaitkus and Eddleman  observed significantly greater (p<0.05) bottlebrush squirreltail
production when associated with large (older) trees compared to small trees. Production of bottlebrush
squirreltail was also significantly greater (p<0.05)
under juniper canopies compared to intercanopy zones. McPherson and others 
observed significantly greater (p<0.01) bottlebrush squirreltail
under Pinchot juniper canopies and at canopy edges compared to areas
beyond canopy, within grazed and relict grasslands
of western Texas. Evaluations by Tueller and Platou  lend
supporting evidence (see: SUCCESSION within the Botanical and Ecological Characteristics section).
Bottlebrush squirreltail does not reduce ponderosa pine seedling growth. Two-year-old pine
seedlings that were planted the 1st postfire spring, after a June wildfire in northern Arizona,
were not affected in height or diameter by competition with bottlebrush squirreltail .
In Arizona ponderosa pine forests, seedlings
normally gain dominance over bottlebrush squirreltail within 5 years .
Bottlebrush squirreltail drastically increased 4 years after a clear-cut within
a lodgepole pine forest of northeastern Utah at 8,800 feet (2,700 m). Bottlebrush
showed the largest increase in vegetative production out of all grasses present :
|1976 (kg/ha)||1980 (kg/ha)|
Bottlebrush squirreltail was an early colonizer after the clear-cut of a
ponderosa pine forest in north-central California .
Bottlebrush squirreltail populations were greatest 11 to 25 years after clearcuts
of a red fir forest in the Sierra Nevada, California .
Everett and Sharow  found bottlebrush squirreltail seed production was less
under singleleaf pinyon (Pinus monophylla)-Utah juniper
woodland canopies than in clearcut areas (1 and 2 postharvest years).
Cultivars, improved and selected materials (and area of origin)
Because of the broad array of subspecies of squirreltail and the genetic variation between species and subspecies, careful identification of the species and subspecies native to the planting site is recommended. Care should be taken to match the appropriate phenotype and genotype of the plant materials with those of the local plant communities to improve the chance of stand success and to prevent genetic contamination of existing populations.
Fish Creek Germplasm, 2003 (E. elymoides ssp. elymoides): This natural track, selected class germplasm was released by the USDA-ARS Forage and Range Research Laboratory in Logan, UT in cooperation with BLM, Utah Agricultural Experiment Station and USDA-NRCS. It was originally collected by T.A. Jones as accession T-1223 in Blaine County, Idaho in August 1995. The native site was described as a big sagebrush and Sandberg bluegrass (Poa secunda Presl.) community at approximately 1450 meters (4,760 feet) elevation. Estimated annual precipitation at the site is 35-38 cm (14-15 in). Fish Creek shows a 33% lighter awn mass as compared to Sand Hollow. The spike also disarticulates in a determinate fashion at the base of the spike, two traits which make Fish Creek easier to harvest and to clean than other releases. Fish Creek is adapted to and intended for use in the Snake River Plain. Second generation seed is maintained by the USDA-ARS Forage and Range Research Laboratory, Logan UT. G3 to G5 seed is available through the Utah Crop Improvement Association.
Toe Jam Creek Germplasm, 2003 (E. elymoides ssp. californicus): This natural track, selected class germplasm was released by the USDA-ARS Forage and Range Research Laboratory in Logan, UT in cooperation with BLM, Utah Agricultural Experiment Station and USDA-NRCS. The original collection for Toe Jam Creek was made in Elko County, Nevada west of Tuscarora by J. Garrison of NRCS. Elevation at the site is 1829 meters (6,000 feet), and average precipitation is estimated at 31cm (12 in.). Toe Jam Creek is intended for use in the lower Snake River Plain and the northern Great Basin. Similar to Fish Creek, Toe Jam Creek exhibits a lower awn mass than Sand Hollow making them presumably easier to remove without damaging the caryopsis. G3 seed is maintained by the USDA-ARS Forage and Range Research Laboratory, Logan UT. Seed through G6 is available through the Utah Crop Improvement Association.
Sand Hollow Germplasm, 1996 (E. multisetus): The Sand Hollow collection site is considerably drier than those typical for big squirreltail. It was originally collected in 1984 in Gem County, Idaho by Greg Painter of NRCS in a bluebunch wheatgrass, Sandberg bluegrass and tapertip hawksbeard (Crepis acuminata Nutt.) community. The collection site is at 830 meters (2,720 feet) elevation and receives an average of 28 centimeters (11.0 inches) annual precipitation. Sand Hollow is considered to be adapted to the mountain foothills of the Snake River Plain region of Idaho and in adjacent regions of Oregon, Nevada and Utah. It was released as a selected class germplasm for high seed production, higher-than-average seed weight and late heading date. G2 seed is maintained by the USDA-ARS Forage and Range Research Laboratory, Logan UT. Seed from G3 and G4 generations are available for seed certification through the Utah Crop Improvement Association.
Tusas Germplasm, 2001 (Elymus elymoides ssp. brevifolius): Tusas Germplasm bottlebrush squirreltail was released by the NRCS and New Mexico State University Agricultural Science Center at Los Lunas, New Mexico. This natural track, selected class release is a composite of eight accessions from throughout New Mexico. Collection site elevations ranged from 1,460 meters (4,800 feet) to 2,800 meters (9,200 feet). From the initial 131 collections, eight were selected for vigor, late flowering and higher seed yield. An equal number of seedlings from each accession were taken to form the composite, Tusas. It is intended for use in the southwestern United States for erosion control, wildlife food and cover, revegetation of disturbed sites and restoration of weed infested rangelands. Breeder and G2 seed are maintained by the NRCS NM Plant Materials Center. Seed is available through the New Mexico Crop Improvement Association.
Pueblo Germplasm and Wapiti Germplasm, 2005 (Elymus elymoides ssp. brevifolius): Pueblo and Wapiti Germplasm are natural track, selected class releases, each originating from a single source. Pueblo was originally collected in 1976 southwest of Pueblo, Colorado in Pueblo County at an elevation of 7,200 feet in shallow, gravelly soils. The original collection of Wapiti was made in 1981 along the Gooseberry Creek drainage in Rio Blanco County, Colorado. The original collection site was in a stony loam soil at 7,800 feet elevation. Eight bottlebrush squirreltail accessions were evaluated by the Upper Colorado Environmental Plant Center (UCEPC) from 1983 to 1987 and compared for forage production, seed production percent stand, leaf height, vigor, leaf abundance and stem height. Of these, two accessions were chosen for further development, Pueblo and Wapiti. Both are intended for use in erosion control and forage production for livestock and wildlife as well as a variety of conservation applications. These releases should be considered as potentially adapted within the natural range of the species. The UCEPC will maintain G1 and G2 seed. G2 seed will be available to growers. Growers may produce one generation (G3) beyond G2 for Pueblo and Wapiti Germplasm seed. Seed used for certified seed production must be obtained from UCEPC.
Contact your local Natural Resources Conservation Service (formerly Soil Conservation Service) office for more information. Look in the phone book under ”United States Government”. The Natural Resources Conservation Service will be listed under the subheading “Department of Agriculture.”
Plant seed in a 36-inch between-row spacing at a rate of 2.4 lbs PLS/acre for 30 PLS per foot of row. Fields should be weed free and have good field moisture to a depth of at least four inches. Soil should be kept moist throughout the germination phase (about 14-28 days). Fifty percent of germination should occur within 15 to 30 days after planting. Broadleaf weeds can be controlled with low rates of bromoxynil at the three to five leaf stage. Always apply herbicides according to label directions. No fertilizer should be applied during the first year to discourage annual weed competition.
Soil moisture should be carefully maintained during early green-up, boot stage, milk stage of seed development and after harvest. No irrigation should be applied during flowering to encourage seed set. Fertilize established fields at 100 lb nitrogen and 40 lb phosphorus per acre in mid-September. Soil testing is recommended to ensure proper rates of fertilization.
Broadleaf weeds can be controlled with herbicides. Application should occur prior to boot stage. Between-row cultivation can be used to control other weeds for the life of the stand.
Seed is ready to harvest in about mid-July of the second growing season (see “management” section for timing). Harvest by windrowing followed by combining. Some report difficulty with mechanical harvesting due to the ready disarticulation of the rachis of mature seed heads. Swathing prior to maturity and curing in windrows will help reduce this problem. Flail-vac and seed stripping harvesting equipment have also been used with varying degrees of success.
Because of the large amount of inert material produced from awns and glumes, this is a very time-consuming species to clean. Thresh seed through a hammer mill to remove awns. Follow with a clipper or other separator. Purity should exceed 90% with greater than 85% viability. Big squirreltail, in particular, has proven difficult to debeard without seed damage. Some seed companies have modified equipment that has resulted in improved seed viability.
Seed yields under irrigated conditions average approximately 200 lb/acre with 190,000 seeds/lb. Harvested seed should be dried to 12% or less moisture before storing. Storing seed in a cool dry environment will retain viability for several years.
Seeds germinate in the fall or spring. Plants green up early and remain green through the fall and into winter. Stands should be protected from heavy grazing, especially during flowering to ensure sufficient seed production to maintain the stand. New plantings should also be protected from grazing for at least two growing seasons. A direct seeded squirreltail stand in a big sagebrush/bluebunch wheatgrass community in south-central Idaho has survived for 30 years with recruitment from natural reseeding.
Wildland seed collection occurs from July to September before disarticulation of the spike. Best germination rates come from seed collected in stands with fifty percent of the seed heads having divergent awns and the other half having straight awns of a reddish color. This occurs approximately one week prior to disarticulation. One hour collecting for a single person averages a yield of about 1.6 oz of clean seed. Seed yields can vary widely depending on stand density and age.
Relevance to Humans and Ecosystems
Value for rehabilitation of disturbed sites
Bottlebrush squirreltail is tolerant of disturbance . The Bureau of Land Management, U.S. Department of the Interior, identifies bottlebrush squirreltail as a high priority species for restoring native plant diversity in the Great Basin and the Columbia River Plateau . Bottlebrush squirreltail naturally colonizes disturbed sites in Yellowstone National Park and is a component of seed mixtures used for restoration of lodgepole pine communities . Brown and Amacher  recommend bottlebrush squirreltail for use in restoration of disturbed arid to semi-arid, desert shrub and pinyon-juniper systems. Bottlebrush squirreltail is well adapted for seeding of Wyoming, black and low sagebrush communities of the Intermountain West, receiving 9 to 13 inches (229-330 mm) annual precipitation. Bottlebrush squirreltail grows well under rabbitbrush canopies in south-central Idaho rangelands .
Bottlebrush squirreltail inhabits xeric sandy soils (73.9% sand, 16.8% silt, 9.2% clay, 1.3% organic matter) of a 50-year-old abandoned tailings pond from a Pb-Zn-processing mill , and is recommended for seed mixtures used to reclaim strip mines in southeastern Montana .
The large ecological amplitude of bottlebrush squirreltail lends to ecotypic differentiation. Phenological differences in growth rate, root:shoot ratios, leaf area, and overall plant size exist between subspecies of bottlebrush squirreltail. Differences are directly related to subspecies distribution . Bottlebrush squirreltail seed source should be considered when implementing revegetation projects. Arredondo and others  observed a higher root length-to-leaf area ratio in plants grown from seed collected from different environments. Differences in phenology between individuals of different habitats are common (see: SEASONAL DEVELOPMENT within the Botanical and Ecological Characteristics section for further information).
Bottlebrush squirreltail seed is available commercially [103,104,134]. The United States Department of Agriculture (USDA), Utah Division of Wildlife Resources, in conjunction with the Intermountain Research Station, Forest Service, USDA, established bottlebrush squirreltail seed quality standards. Seed quality standards as of 1990 are summarized below :
|Seed unit1||Acceptable purity (%)2||Acceptable viability (%)2|
|spikelet with or without awns||90||85|
1 Reproductive structure marketed as seed.
2 Purity (%) and germination (%) expected using seed quality testing rules in seeds of commercial quality.
Germinability of primed bottlebrush squirreltail seed significantly (p<0.05) decreases when dried and stored .
Competition with invasive weeds:
The persistence of bottlebrush squirreltail in areas invaded by exotic weeds is well recognized. Bottlebrush squirreltail persists in areas infested with cheatgrass [9,18,99,100,103,188], medusahead (Taeniatherum caput-medusae) [9,96,169,213,216], and Japanese brome (Bromus japonicus) .
Bottlebrush squirreltail naturally invades rangelands dominated by cheatgrass and medusahead . However, mechanisms behind bottlebrush squirreltail's ability to occupy weed-infested areas are not completely understood. Several studies have evaluated the persistence of bottlebrush squirreltail within cheatgrass infested ranges. Beckstead  found recently harvested bottlebrush squirreltail seeds from mountain brush and meadow sites to possess lower levels of dormancy than cheatgrass at higher temperatures, 68/86 degrees Fahrenheit (20/30 C), whereas the opposite was true of lower temperatures, 41/59 degrees Fahrenheit (5/15 C). Bottlebrush squirreltail at lower elevations (4,100 feet (1,250 m)) have a greater probability of autumn germination than cheatgrass . Established bottlebrush squirreltail plants generally initiate growth before the rosettes of cheatgrass in desert rangelands of Nevada . Beckstead  suggests fall seeding of bottlebrush squirreltail into cheatgrass infested rangelands.
Early spring growth and ability to grow at low temperatures contribute to the persistence of bottlebrush squirreltail among cheatgrass dominated ranges . Bottlebrush squirreltail seedlings have the ability to grow roots at low soil temperatures, allowing for soil penetration similar to medusahead and cheatgrass in the northern regions of the Great Basin. Root development at low temperatures promotes bottlebrush squirreltail seedling establishment and effective competition with medusahead .
Bottlebrush squirreltail has potential to outcompete medusahead. Management goals often concentrate on protecting bottlebrush squirreltail seedlings from livestock and rabbits, along with maintaining a natural supply of seed . Hironaka and Sindelar  evaluated bottlebrush squirreltail growth under greenhouse conditions, when closely associated with medusahead. Bottlebrush squirreltail plants (10 plants) were observed in combination with 0, 4, 12, 36, 108, and 324 medusahead/foot2. Bottlebrush squirreltail growth was not affected by medusahead until 5 weeks old, grown under densities of 108 and 324 medusahead/foot2. Although stunted, no bottlebrush squirreltail mortality was seen at all densities tested, whereas a large amount of medusahead mortality was observed in the 324 medusahead/foot2 level. Bottlebrush squirreltail acquired greater root carbohydrate reserves than medusahead under competitive conditions. Under proper management, Hironaka  suggests a successional sequence of cheatgrass to medusahead to bottlebrush squirreltail dominated sites for northern Great Basin areas receiving greater than 11 inches (279 mm) precipitation.
Rome and Eddelman  compared bottlebrush squirreltail seedling growth in competition with Japanese brome at densities of 0, 50, 100, 200, 400 Japanese brome/m2. Observations were made in Missoula, Montana at 23, 42, 56, 82, and 97 days following an 8 April seeding of bottlebrush squirreltail and Japanese brome. Bottlebrush squirreltail averaged 85% survival in areas without Japanese brome, compared to an average of 66% survival from areas with 100 to 400 Japanese brome/m2 (p<0.05). Overall, bottlebrush squirreltail under competition with Japanese brome showed the greatest competitive ability at 100 Japanese brome/m2.
Martlette and Anderson  observed poor bottlebrush squirreltail seed dispersal into adjacent crested wheatgrass (Agropyron cristatum) stands. Plant cover acted as a barrier restricting the dispersal capabilities of bottlebrush squirreltail.
Under greenhouse conditions, Schlatterer and Tisdale  found sagebrush leaf litter to significantly (p<0.05) decrease bottlebrush squirreltail germination compared to moss and rabbitbrush (Chrysothamnus spp.) litter. The average number of bottlebrush squirreltail seeds (20 seeds/pot) germinating under different litter treatments is summarized below:
|Big sagebrush||Moss||Rabbitbrush||No litter|
Bottlebrush squirreltail will readily establish in pinyon-juniper tree litter when a fermentation layer is not present .
Robertson  observed seeded bottlebrush squirreltail within a big sagebrush habitat at 5,200 feet (1,585 m) in northern Nevada to be short lived, persisting for 5 years. Bottlebrush squirreltail persisted for 30 years following direct seeding within a big sagebrush/bluebunch wheatgrass site in south-central Idaho .
Importance to Livestock and Wildlife
In southeastern Oregon salt desert-shrub ranges, bottlebrush squirreltail is an important component of domestic livestock seasonal diets. Winter months show greatest use [83,140].
|Small nongame birds||Fair||Good|
|Upland game birds||Fair||Fair|
open and timbered ponderosa pine
overstories in Arizona.
Greater digestibility and significantly (p<0.05) higher crude protein
were found in open versus timbered overstories:
|Crude protein (%)||16.0||9.7|
squirreltail nutrient levels fluctuate throughout the growing season. Levels
of S, P, and K usually drop
from March to October. Amounts of Mg and Ca stay relatively the same with
high points in spring, late summer, and early fall . Overall,
bottlebrush squirreltail is a poor source of phosphorus, carotene, and digestible
protein, but a good source of energy . The
average chemical composition (%) of bottlebrush squirreltail in Great Basin desert ranges
is summarized below :
|Gross energy||1730 (kcal/lb)|
Intermountain ranges. Domestic sheep relish the green foliage . Overall, bottlebrush
squirreltail is considered moderately palatable to livestock.
When present, the long sharp awns of bottlebrush squirreltail greatly reduce
its palatability . Mature awns may penetrate flesh around the mouth of grazing
animals, producing inflammation [51,115]. Eye and ear injury may also occur .
Reclamation/re-vegetation: Squirreltail displays many qualities which make it a good choice for what has been described as “assisted succession.” It is a short-lived perennial grass which can act as an early-seral species by competing with and replacing annual weedy species following fire. It is thought that after squirreltail establishes, annual weedy species should decrease in frequency and longer-lived, native perennials may be more successfully reseeded and established.
Its ability to germinate in the late fall and very early spring at a wide range of temperatures add to its capability to compete with cheatgrass (Bromus tectorum L.). Studies also indicate that squirreltail is capable of establishing in medusahead wildrye (Taeniatherum caput-medusae (L.) Nevski) infested sites. This makes squirreltail one of the more competitive native grasses available for reseeding disturbed rangelands. It is also a self-fertilizing species which allows it to produce seed despite sparse stands following seeding.
Squirreltail is considered to be one of the most fire resistant native bunchgrasses. Older plants contain relatively low amounts of dead material when compared with other native bunchgrasses. This allows for hot, but quick burns which do not penetrate and damage the crown. However, during dry years plants can be damaged by severe burns. As an early-seral species, new plants often increase for two to three years following burns.
Erosion control: When in large, dense stands, squirreltail is very effective at controlling wind and water erosion, due to its persistent ground cover.
Forage/wildlife: Squirreltail is considered to be fair to desirable forage for cattle, horses and sheep in spring before seed head development and late summer to fall after seed shatter. The long, sharp awns of the florets and glumes can be injurious to grazing animals during mid to late spring into summer. Leaves green up in very early spring and are palatable through the fall, especially following rain. The tendency for some leaves to remain green through the winter makes squirreltail an important, though not especially nutritious, winter forage species. Table 1 shows crude protein levels for the spring, summer and winter.
Table 1. Crude protein levels by season
% Crude protein
(Adapted from Monsen et al, 2004)
Elymus elymoides is a species of wild rye known by the common name squirreltail. This grass is native to most of North America west of the Mississippi River. It occurs in a number of ecosystems, from the alpine zone to desert sage scrub to valley grassland.
Elymus elymoides is a perennial bunch grass growing to around half a meter in height. Its erect solid stems have flat or rolled leaf blades. The inflorescence is up to 15 centimeters long and somewhat stiff and erect, with spikelets one or two centimeters long not counting the awn, which may be 9 centimeters long and sticks straight out, making the inflorescence look like a bottlebrush.
This grass is considered a very good forage for sheep. It is best for grazing during the winter, when it is small and green. It becomes less palatable to livestock when its awns grow long and sharp at maturity.
- E. e. ssp. brevifolius - widespread
- E. e. ssp. californicus - occurs in the western half of the species range
- E. e. ssp. elymoides - widespread
- E. e. ssp. hordeoides - limited mostly to the Pacific Northwest
- Media related to Elymus elymoides at Wikimedia Commons
- Data related to Elymus elymoides at Wikispecies
- Jepson Manual Treatment: Elymus elymoides
- USDA Plants Profile: Elymus elymoides (squirreltail)
- Elymus elymoides — U.C. Photo gallery
|This Pooideae article is a stub. You can help Wikipedia by expanding it.|
Names and Taxonomy
Comments: Though bottlebrush and big squirreltail are commonly referred to as Sitanion hystrix (Nutt.) J.G. Smith and Sitanion jubatum J.G. Smith, respectively, squirreltail is becoming more widely accepted through cytological and molecular evidence as belonging to the genus Elymus. The squirreltail complex, Elymus section Sitanion, is composed of two species, E. multisetus (J.G. Sm.) M.E. Jones (big squirreltail) and E. elymoides (Raf.) Swezey (bottlebrush squirreltail), with E. elymoides being further divided into four subspecies: elymoides, brevifolius (J.G. Sm.) Barkworth, californicus (J.G. Sm.) Barkworth, and hordeoides (Suksd.) Barkworth (Barkworth and Dewey, 1985; Kartesz, 1999).
(Raf.) Swezey [60,87,113] (Poaceae). Barkworth and Dewey  realigned Sitanion hystrix (Nuttall) J. G. Smith
in the Elymus genus as Elymus elymoides. Realignment of the Elymus genus
is based upon morphological and genomic characters [12,56].
The following subspecies are currently recognized: Elymus elymoides ssp. brevifolius,
E. e. ssp. californicus, E. e. ssp. elymoides, and E.
e. ssp. hordeoides .
Bottlebrush squirreltail hybridizes frequently with other
Elymus species and infrequently with Hordeum species .
Bottlebrush squirreltail also hybridizes with saline wildrye (Leymus salinus)
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