SPECIES: Hesperostipa comata
Zlatnik, Elena. 1999. Hesperostipa comata.
In: Fire Effects Information System, [Online].
U.S. Department of Agriculture, Forest Service,
Rocky Mountain Research Station, Fire Sciences Laboratory (Producer).
Available: http://www.fs.fed.us/database/feis/ .
The fully documented scientific name of needle-and-thread grass is Hesperostipa comata (Trin. & Rupr.) Barkworth (Poaceae) [79,129]. There are 2 recognized subspecies, H. c. ssp. comata, and H. c. ssp. intermedia (Scribner & Tweedy) Barkworth . Some authors identify these infrataxa as varieties [36,80,87].
No special status
Needle-and-thread grass grows throughout the western and midwestern United States and Canada, from the Yukon to California, east to Ontario, Indiana, and Texas, and south into Mexico. There are outlying populations in Rhode Island and New York [79,122].
FRES21 Ponderosa pine
FRES30 Desert shrub
FRES31 Chaparral-mountain shrub
FRES36 Mountain grasslands
FRES38 Plains grasslands
FRES40 Desert grasslands
AZ   CA CO ID IL
KS MI MN MS MO MT NE
NV NM NY ND OK OR RI
SD TX UT WA WI WY
AB BC MB NT ON SK YK
1 Northern Pacific Border
2 Cascade Mountains
3 Southern Pacific Border
4 Sierra Mountains
5 Columbia Plateau
6 Upper Basin and Range
7 Lower Basin and Range
8 Northern Rocky Mountains
10 Wyoming Basin
12 Colorado Plateau
13 Rocky Mountain Piedmont
14 Great Plains
15 Black Hills Uplift
16 Upper Missouri Basin and Broken Lands
K011 Western ponderosa forest
K016 Eastern ponderosa forest
K017 Black Hills pine forest
K018 Pine-Douglas-fir forest
K019 Arizona pine forest
K022 Great Basin pine forest
K023 Juniper-pinyon woodland
K024 Juniper steppe woodlands
K037 Mountain-mahogany-oak scrub
K038 Great Basin sagebrush
K055 Sagebrush steppe
K056 Wheatgrass-needlegrass shrubsteppe
K057 Galleta-threeawn shrubsteppe
K063 Foothills prairie
K070 Sandsage-bluestem prairie
K075 Nebraska Sandhills prairie
K086 Juniper-oak savanna
210 Interior Douglas-fir
220 Rocky Mountain juniper
237 Interior ponderosa pine
101 Bluebunch wheatgrass
105 Antelope bitterbrush-Idaho fescue
110 Ponderosa pine-grassland
301 Bluebunch wheatgrass-blue grama
302 Bluebunch wheatgrass-Sandberg bluegrass
303 Bluebunch wheatgrass-western wheatgrass
304 Idaho fescue-bluebunch wheatgrass
310 Needle-and-thread-blue grama
311 Rough fescue-bluebunch wheatgrass
314 Big sagebrush-bluebunch wheatgrass
317 Bitterbrush-bluebunch wheatgrass
320 Black sagebrush-bluebunch wheatgrass
322 Curlleaf mountain-mahogany-bluebunch wheatgrass
401 Basin big sagebrush
403 Wyoming big sagebrush
404 Threetip sagebrush
405 Black sagebrush
406 Low sagebrush
412 Juniper-pinyon woodland
413 Gambel oak
414 Salt desert shrub
415 Curlleaf mountain-mahogany
602 Bluestem-prairie sandreed
603 Prairie sandreed-needlegrass
605 Sandsage prairie
611 Blue grama-buffalograss
613 Fescue grassland
720 Sand bluestem-little bluestem (dunes)
721 Sand bluestem-little bluestem (plains)
722 Sand sagebrush-mixed prairie
724 Sideoats grama-New Mexico feathergrass-winterfat
Needle-and-thread grass appears in many habitat types, including forested, grassland, and shrub-steppe communities.
In Utah, needle-and-thread grass occurs in the wheatgrass-bluegrass (Triticeae-Poa spp.) rangelands with bluebunch wheatgrass (Pseudoroegneria spicata), Sandberg bluegrass (Poa secunda), Cusick bluegrass (P. cusickii), Indian ricegrass (Achnatherum hymenoides), sand dropseed (Sporobolus cryptandrus), globemallow (Sphaeralcea spp.), balsamroot (Balsamorhiza spp.), yarrow (Achillea spp.), phlox (Phlox spp.), paintbrush (Castilleja spp.), and milkvetch (Astragalus spp.) .
Needle-and-thread grass also appears in the saltbush-greasewood (Atriplex spp.-Sarcobatus spp.) type in Utah with shadscale (Atriplex confertifolia), rabbitbrush (Chrysothamnus spp.), winterfat (Krascheninnikovia lanata), budsage (Artemisia spinescens), greenmolly (Kochia americana), spineless horsebrush (Tetradymia canescens), hopsage (Grayia spp.), Gardner's saltbush (Atriplex gardneri), Indian ricegrass, sand dropseed, galleta (Hilaria jamesii), greasewood, saltgrass (Distichlis spp.), alkali sacaton (Sporobolus airoides), seepweed (Suaeda spp.), and pickleweed (Allearolfea occidentalis) .
Other common associates of needle-and-thread grass include Utah juniper (Juniperus osteosperma), Colorado pinyon (Pinus edulis), ponderosa pine (P. ponderosa), big sagebrush (Artemisia tridentata), black sagebrush (A. nova), sand sagebrush (A. filifolia), low sagebrush (A. arbuscula), silver sagebrush (A. cana), threetip sagebrush (A. tripartita), antelope bitterbrush (Purshia tridentata), serviceberry (Amelanchier spp.), Idaho fescue (Festuca idahoensis), threadleaf sedge (Carex filifolia), mountain muhly (Muhlenbergia montana), prairie junegrass (Koeleria macrantha), elk sedge (Carex geyeri), big bluestem (Andropogon gerardii), and prairie sandreed (Calamovilfa longifolia).
Vegetation typings in which needle-and-thread appears as a dominant include:
Vegetation and soils of the Rock Springs Watershed 
Vegetation and soils of the Duckwater Watershed 
Habitat types of the Curlew National Grassland, Idaho 
A reconsideration of grassland classification in the northern Great Plains of North America 
Forest vegetation of eastern Washington and northern Idaho 
Structure and ecology of coniferous forests of the northern Rocky Mountains 
Plant communities and habitat types in the Lava Beds National Monument, California 
The many faces of South Dakota rangelands: description and classification 
Selected habitat types of the Custer National Forest 
The vegetation of the Grand River/Cedar River, Sioux, and Ashland Districts of the Custer National Forest: a habitat type classification 
The vegetation of Theodore Roosevelt National Park, North Dakota: a habitat type classification 
Characteristics of the Stipa comata-Bouteloua gracilis-Bouteloua curtipendula association in northern Colorado 
The vegetation of Alberta 
Aspen community types of the Intermountain Region 
Needle-and-thread grass is widespread throughout the West and can be important to livestock and wildlife, especially early in the spring. The plant is preferred forage of black-tailed jackrabbits [4,38], black-tailed prairie dogs, northern pocket gophers , and desert cottontails .
Needle-and-thread grass is moderately palatable to wildlife and domestic stock. The plant provides highly palatable early spring forage in Utah and fodder in fall and winter, but the summer fruit has a sharp awn that may injure grazing animals, especially domestic sheep [21,78,85,128,130]. Throughout the West, needle-and-thread grass is moderately important spring forage for mule deer, but use declines considerably as more preferred forages become available in summer .
Animal use of needle-and-thread grass is as follows [11,38,51,67,69,72,81,94,107,117,126]:
|Elk||----||----||medium||----||medium (in Oct.)|
|Crude fiber (%)||29.0|
|Ether extract (%)||2.6|
|N-free extract (%)||44.1|
|Vit. A equiv. (IU/g)||147.0|
Needle-and-thread grass is useful for stabilizing eroded or degraded sites [79,94,115]. The presence of the long and tough seed awn on needle-and-thread grass reduces is usefulness as a commercial seed , but needle-and-thread grass hay has been used successfully in revegetation projects. In Saskatchewan, needle-and-thread grass and Canadian needlegrass (Hesperostipa spartea) mulch was used as a seed source and erosion blanket on a steep south-facing slope . At a mining revegetation site near Colstrip, Montana, needle-and-thread grass successfully established on plots covered in native hay harvested locally on July 6. Ninety-two percent of the cover at the site from which the hay was harvested was needle-and-thread grass.
A south-facing slope on a sodium chloride contaminated mine site in North Dakota was vegetated with a mix of native grasses including needle-and-thread grass. Establishment of needle-and-thread grass after 2 years was still very low and insignificantly better on the actively reclaimed site than on the control .
Needle-and-thread grass greens up early in the spring [65,78] and may be subject to overgrazing if other forage is not available . The plant goes dormant in summer, but given sufficient moisture, needle-and-thread grass will green up again in the fall . The plant is particularly sensitive to defoliation from June 1 to July 31 . Clipping treatments in an Idaho study caused the highest mortality in July and August . Needle-and-thread grass is considered a decreaser under domestic livestock grazing pressure by most authors [8,13,23,25,26,28,33,45,84,113,120,], although others claim needle-and-thread grass increases under or is unaffected by grazing pressure [2,3,25,50,85,86,88,97]. At the Idaho National Engineering Laboratory Site, relative cover and density of needle-and-thread grass significantly (p<0.05) increased over 10 years of cattle grazing in a big sagebrush (Artemisia tridentata)/Indian ricegrass (Achnatherum hymenoides)-needle-and-thread grass habitat type .
Prairie dog activity can have a profound effect on needle-and-thread grass communities. Only 2 years after the establishment of a black-tailed prairie dog colony on a South Dakota buffalograss (Buchloe dactyloides)-Kentucky bluegrass (Poa pratensis)-needle-and-thread grass site, needle-and-thread grass no longer dominated. By 4 to 6 years of colonization, needle-and-thread grass had dropped from 97% frequency to less than 10% frequency [5,6].
Needle-and-thread grass is a cool-season, native, perennial bunchgrass . The bunches are small, from 1 to 3 inches (2.5-7.6 cm) in diameter, and widely spaced .
Needle-and-thread grass is shallow-rooted  to medium-rooted and produces numerous fibrous roots of 0.04 inches (1 mm) or less in diameter . Roots grow both vertically and laterally, more than 14 inches (36 cm) from the base of the plant in the first 0.5 foot (0.15 m) of soil. These profusely branched roots reach 3 to more than 5 feet (0.9-1.5 m) deep [34,57,116,127,126,128], but more than 50% of the total root biomass is within the first 0.6 foot (0.2 m) of soil . In a Saskatchewan prairie, number of roots per shoot of needle-and-thread grass averaged 3.8 to 5.4, and the mean number of lateral roots per decimeter of main root was 39 to 75 .
Needle-and-thread grass is moderately to highly drought resistant [10,101,116,128] and recovers well from drought [53,116].
Needle-and-thread grass is colonized by vesicular-arbuscular mycorrhizae (VAM). In a study in northern Nevada, 83% of plants within a grazing exclosure were colonized with VAM, while only 33% of grazed plants were colonized, a significant (p<0.05) difference .
Propagation is by seed  and by tillers [1,46,128]. Seeds are long-lived. Sixty-three percent of seeds stored in an open warehouse in Utah germinated after 9 years . Seeds may germinate in spring or fall, but more commonly in the fall .
Because of a long awn on the seed, needle-and-thread grass seeds can imbed themselves in the soil by a twisting action of the awn in response to daily humidity changes [52,92].
Needle-and-thread grass seeds are not a prominent component of soil seedbanks. Hassan and West  studied soil seedbank properties under burned and unburned Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis)-Utah juniper-bunchgrass sites in Utah. Despite relatively high presence of needle-and-thread grass as ground cover, there were very few viable needle-and-thread grass seeds in the upper 2 inches (5 cm) of soil on both the burned and unburned treatments.
In a Nebraska sandhills prairie site, needle-and-thread grass contributed the fewest seeds to the 0 to 2 inch (0-5 cm) depth seedbank of several perennial grasses . Only 2% of needle-and-thread grass seeds germinated in greenhouse germination trials.
Needle-and-thread grass is common on dry hills and plains, and on stony and sandy soils throughout its range [36,130]. Soils are usually slightly high pH, low water-holding capacity, low clay percentage and high bulk density . On the Upper Snake River Plains in Idaho, needle-and-thread grass is common on sandy soils and dry areas . In southwestern Saskatchewan, needle-and-thread grass often dominates on loam soils but is usually absent from heavy clays .
Needle-and-thread grass occurs on well-drained soils from 660 to 11,550 feet (200-3500 m) in California . In Arizona, needle-and-thread grass occurs from 3,500 to 8,500 feet (1061-2576 m) on dry hills, open woods, and sandy soils, often with juniper . In Montana, needle-and-thread is found from 2,000 to 8,000 feet (606-2424) . In Utah, needle-and-thread occurs from 3,498 to 10,065 feet (106-3050 m) .
Needle-and-thread grass generally requires at least 10 inches (254 mm) of annual precipitation  but grows in areas with less . In Montana, needle-and-thread grass grows best with 10-18 inches (254-457 mm) of precipitation . The aspect on which needle-and-thread grass appears most frequently varies by geographic location. In the sandhills of Nebraska, needle-and-thread grass is commonly found on north-facing slopes . In Saskatchewan, needle-and-thread grass reaches highest densities on warm, dry, upper, south-facing slopes . In Alberta, needle-and-thread grass is largely restricted to south-facing slopes and is most dense on the upper slopes . In eastern Colorado, needle-and-thread grass is most common on north and east-facing slopes .In Montana, needle-and-thread grass performs worst on southwest slopes .
At the Idaho National Engineering Laboratory Site, density and frequency of needle-and-thread grass was significantly (p<0.01) correlated with April precipitation, but not with May or June precipitation .
Needle-and-thread grass is generally a mid-seral species. Needle-and-thread is considered an early seral species in Montana  and Wyoming , following the 1st annual forbs and grasses and biennial forbs. Needle-and-thread grass is a mid-successional species in semi-arid big sagebrush communities in Colorado .
Freeman and Emlen  evaluated interspecific competition in a cold desert shrub community in western Utah. They found needle-and-thread grass was negatively affected by competition with Indian ricegrass, galleta, blue grama (Bouteloua gracilis), shadscale, saltbush, winterfat, and cheatgrass (Bromus tectorum), and positively associated with the forbs sand dropseed and red threeawn (Aristida purpurea).
Germination of needle-and-thread grass seeds is strongly inhibited by aqueous extracts of absinth wormwood (Artemisia absinthium) but positively affected by extracts of fringed sagewort (A. frigida) and tarragon (A. dracunculus) .
In wetter than average moisture conditions, needle-and-thread grass may be replaced by wheatgrass (Triticeae) and Canadian needlegrass .
Needle-and-thread grass becomes dormant during hot weather, but it will green up again in the fall given sufficient precipitation [92,128]. According to Wright , needle-and-thread grass never becomes truly dormant in the summer in Idaho.
Seasonal development of needle-and-thread grass in the Great Plains is as follows :
|Growth resumes||Late March, early April|
|Ripe seeds shed||July|
|Heads fully out||6/18|
|Flowers in bloom||6/22|
The fire took place on September 14, 1995. Temperatures were 82 to 84 degrees Fahrenheit (28-29 oC), relative humidity was 17%, and winds were 8 to 12 miles/h (13-19 km/h).
The burn took place at Iron Springs Bench, Dinosaur National Monument, Dinosaur, Colorado.
The study plots represented two prefire communities--a big sagebrush (Artemisia tridentata)/grass community dominated by sagebrush, thickspike wheatgrass (Elymus lanceolatus), needle-and-thread grass (Hesperostipa comata), and Indian ricegrass (Achnatherum hymenoides), and a perennial grassland featuring the same grass species.
Grasses were dormant, mature plants with current year inflorescences.
Fire behavior on the big sagebrush/grass plots was as follows:
|Rate of spread||flame length||flaming front||residence time in sagebrush|
|1809-2010 m/h||3 m||3-4.5 m||20 sec. or less|
Fire characteristics were not measured in the perennial grass plot. However, residence time was apparently lower, around 10 seconds, due to lower fuel loading.
On the sagebrush/grass plots, 74% of needle-and-thread grass plants regenerated from the caudex in 1996, the year following the burn. In 1996, only 4% of the surviving plants produced seed, but by 1997, 100% produced seed. In 1997, 6 plants that were absent (and presumed killed) in 1996 resprouted and produced seed, and 5 plants present in 1996 were not found in 1997.
On the perennial grass plots, 92% of plants regenerated from the caudex in 1996, 1 year after the burn. By 1997, regeneration was 99%. In 1996, 14% of plants produced seed, but by 1997, 99% did.
Needle-and-thread grass regenerates following fire from the surviving underground root system. Plants that fail to regenerate or produce seed in the 1st season following fire may still recover in the 2nd year.
Zlatnik, Elena, compiler. 1999. Effects of prescribed fire on needle-and-thread grass in a Idaho big sagebrush/bunchgrass community on the Snake River Plains. In: Hesperostipa comata. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/ [ ].
Blaisdell, James P. 1953. Ecological effects of planned burning of sagebrush-grass range on the Upper Snake River Plains. Tech. Bull. 1975. Washington, DC: U.S. Department of Agriculture. 39 p. .
August 1936/severity not given
U.S. Sheep Experiment Station, 11 miles northeast of Dubois, Clark County, Idaho
This was a big sagebrush (Artemisia tridentata)/bunchgrass site, with 35% perennial grasses, including thickspike wheatgrass (Elymus lanceolatus), plains reedgrass (Calamagrostis montanesis), sedges (Carex spp.), junegrass (Koeleria macrantha), Sandberg bluegrass (Poa secunda), and needle-and-thread grass (Hesperostipa comata); 5% perennial forbs; 5% annual forbs; 40% big sagebrush; and 15% downy rabbitbrush (Chrysothamnus viscidiflorus var. puberulus), spineless gray horsebrush (Tetradymia canescens var. inermis), and miscellaneous other shrubs.
Seeds had been disseminated and plants were dry or nearly dry. The site had not been grazed the previous growing season in order to have sufficient fuels to carry the fire.
The study site was at approximately 6,000 feet (1830 m) elevation, with 11 inches (279 mm) annual precipitation, with sandy soils of basaltic origin. Dry southwestern winds during the summer months make this an arid site, with 100 degrees Fahrenheit (38°C) temperatures possible in the summer and -35 degrees Fahrenheit (-37°C) in the winter.
The fire burned in a mosaic pattern, with scattered unburned islands. Immediately following the burn, the study plots were classified according to the following definitions: 1) heavily burned—trunk or main stem of big sagebrush consumed, 2) moderately burned—larger branches of sagebrush remaining but smaller ones consumed, 3) lightly burned—only leaves consumed, and 4)unburned—no evidence of fire in brush or understory.
Production of needle-and-thread grass following the fires was not significantly different under any treatment.
The author concluded that needle-and-thread grass would experience a 1st year set back in production following burning, and then increase production in the following years. Needle-and-thread grass was not reduced by the burn.
Zlatnik, Elena, compiler. 1999. Needle-and-thread grass response to spring burning in western South Dakota. In: Hesperostipa comata. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/ [ ].
Gartner, F. R.; Lindsey, J. R. 1986. Vegetation responses to spring burning in western South Dakota. In: Clambey, Gary K.; Pemble, Richard H., eds. The prairie: past, present and future: Proceedings, 9th North American prairie conference; 1984 July 29 - August 1; Moorhead, MN. Fargo, ND: Tri-College University Center for Environmental Studies: 143-146. .
April 21, 1976/severity not given
Wind Cave National Park, Black Hills, South Dakota.
This was a ponderosa pine (Pinus ponderosa) and mixed-grass prairie site, featuring a western wheatgrass (Pascopyrum smithii)-needle-and-thread grass plant community. Species present included green needlegrass (Nassella viridula), bluegrasses (Poa spp.), grama grasses (Bouteloua spp.), sedges (Carex spp.), forbs, and shrubs.
Needle-and-thread grass was in early growth.
The study area was located on a nearly level bench, with average annual precipitation of 16.6 inches (422 mm), mostly in the summer. The soils in the study area were deep silt loams, derived from underlying gypsiferous red shales. Silty clay subsoils layers were calcareous at about 15 inches (38 cm).
Conditions at the time of the fire were: winds southeast 8 to 12 mph (19-24 km/h), temperature 70 degrees Fahrenheit (20 °C), and relative humidity 40%. Most of the area was burned with a strip-headfire and a flank fire, due to shifting winds.
In 1976, the year of the fire, needle-and-thread grass yield was significantly (p<0.10) higher in the burn than in the unburned control. In the following year, yield was significantly lower. The year following the burn received lower than average annual precipitation, and mean yields of all vegetation measured were lower on both burned and unburned plots. The authors attributed this decrease to droughty conditions.
Flowering was stimulated on the burned needle-and-thread grass plots for the 1st season following the fire (1976).
The authors concluded that burning increased the yields of desirable native species, decreased the presence of exotics, and had a net benefit on the health of the study sites.
1. Akinsoji, Aderopo. 1988. Postfire vegetation dynamics in a sagebrush steppe in southeastern Idaho, USA. Vegetatio. 78: 151-155. 
2. Alldritt-McDowell, Judith; Coupe, Ray. 1998. The ecology of the bunchgrass zone. QP #004216. Victoria, BC: Ministry of Forests, Research Branch. 5 p. 
3. Anderson, Jay E.; Jeppson, R. J.; Wildosz, R. J.; [and others]. 1978. Trends in vegetation development on the Idaho National Engineering Laboratory Site. In: Markham, O. D., ed. Ecological studies on the Idaho National Engineering Laboratory Site: 1978 Progress Report. IDO-112087. Idaho Falls, ID: U.S. Department of Energy, Environmental Sciences Branch, Radiological and Environmental Sciences Lab: 144-166. 
4. Anderson, Jay E.; Shumar, Mark L. 1986. Impacts of black-tailed jackrabbits at peak population densities on sagebrush vegetation. Journal of Range Management. 39(2): 152-155. 
5. Archer, Steve; Garrett, M. G.; Detling, James K. 1987. Rates of vegetation change associated with prairie dog (Cynomys ludovicianus) grazing in North American mixed-grass prairie. Vegetatio. 72: 159-166. 
6. Archer, Steven R. 1983. Plant community structure, competitive interactions and water relations as influenced by herbivores. Fort Collins, CO: Colorado State University. 114 p. Dissertation. 
7. Bailey, Arthur W.; Anderson, Murray L. 1978. Prescribed burning of a Festuca-Stipa grassland. Journal of Range Management. 31: 446-449. 
8. Baker, William L.; Kennedy, Susan C. 1985. Presettlement vegetation of part of northwestern Moffat County, Colorado, described from remnants. The Great Basin Naturalist. 45(4): 747-783. 
9. Banner, Roger E. 1992. Vegetation types of Utah. Journal of Range Management. 14(2): 109-114. 
10. Barnes, P. W.; Harrison, A. T.; Heinisch, S. P. 1984. Vegetation patterns in relation to topography and edaphic variation in Nebraska Sandhills prairie. Prairie Naturalist. 16(4): 145-157. 
11. Beale, Donald M.; Smith, Arthur D. 1970. Forage use, water consumption, and productivity of pronghorn antelope in western Utah. Journal of Wildlife Management. 34(3): 570-582. 
12. Bernard, Stephen R.; Brown, Kenneth F. 1977. Distribution of mammals, reptiles, and amphibians by BLM physiographic regions and A.W. Kuchler's associations for the eleven western states. Tech. Note 301. Denver, CO: U.S. Department of the Interior, Bureau of Land Management. 169 p. 
13. Bethlenfalvay, Gabor J.; Dakessian, Suren. 1984. Grazing effects on mycorrhizal colonization and floristic composition of the vegetation on a semiarid range in northern Nevada. Journal of Range Management. 37(4): 312-316. 
14. Blackburn, Wilbert H.; Eckert, Richard E., Jr.; Tueller, Paul T. 1971. Vegetation and soils of the Rock Springs Watershed. R-83. Reno, NV: University of Nevada, Agricultural Experiment Station. 116 p. In cooperation with: U.S. Department of the Interior, Bureau of Land Management. 
15. Blackburn, Wilbert H.; Tueller, Paul T.; Eckert, Richard E., Jr. 1968. Vegetation and soils of the Duckwater Watershed. Reno, NV: University of Nevada, College of Agriculture. 81 p. In cooperation with: U.S. Department of the Interior, Bureau of Land Management. 
16. Blaisdell, James P. 1953. Ecological effects of planned burning of sagebrush-grass range on the Upper Snake River Plains. Tech. Bull. 1975. Washington, DC: U.S. Department of Agriculture. 39 p. 
17. Blaisdell, James P. 1958. Seasonal development and yield of native plants on the upper Snake River Plains and their relation to certain climatic factors. Tech. Bull. 1190. Washington, DC: U.S. Department of Agriculture. 68 p. 
18. Blank, Robert R.; Young, James A. 1998. Heated substrate and smoke: influence on seed emergence and plant growth. Journal of Range Management. 51(5): 577-583. 
19. Blinn, Dean W.; Habeck, James R. 1967. An analysis of morainal vegetation in the upper Blackfoot Valley, Montana. Northwest Science. 41(3): 126-140. 
20. Bock, Jane H.; Bock, Carl E. [n.d.]. Some effects of fire on vegetation and wildlife in ponderosa pine forests of the southern Black Hills. Final Report. Contracts CX-1200-9-B034, CX-1200-0-B018, CX-1200-1-B022; Grant No. RM-80-105 GR. Unpublished report on file with: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Lab, Missoula, MT. 58 p. 
21. Booth, D. Terrance. 1987. Diaspores of rangeland plants: ecology and management. In: Frasier, Gary W.; Evans, Raymond A., eds. Proceedings of symposium: "Seed and seedbed ecology of rangeland plants"; 1987 April 21-23; Tucson, AZ. Washington, DC: U.S. Department of Agriculture, Agricultural Research Service: 202-211. 
22. Bradley, Anne F.; Noste, Nonan V.; Fischer, William C. 1992. Fire ecology of forests and woodlands of Utah. Gen. Tech. Rep. INT-287. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 128 p. 
23. Bragg, Thomas B. 1978. Effects of burning, cattle grazing, and topography on vegetation of the choppy sands range site in the Nebraska Sandhills Prairie. In: Hyder, Donald N., ed. Proceedings, 1st international rangeland congress; 1978 August 14-18; Denver, CO. Denver, CO: Society for Range Management: 248-253. 
24. Bramble-Brodahl, Mary K. 1978. Classification of Artemisia vegetation in the Gros Ventre area, Wyoming. Moscow, ID: University of Idaho; 1978. 126 p. Thesis. 
25. Brand, M. D.; Goetz, H. 1978. Secondary succession of a mixed grass community in southwestern North Dakota. Annual Proceedings of the North Dakota Academy of Science. 32(2): 67-78. 
26. Brand, Michael D. 1980. Secondary succession in the mixed grass prairie of southwestern North Dakota. Fargo, ND: North Dakota State University. 77 p. Dissertation. 
27. Brand, Michael D.; Goetz, Harold. 1986. Vegetation of exclosures in southwestern North Dakota. Journal of Range Management. 39(5): 434-437. 
28. Clarke, S. E.; Tisdale, E. W.; Skoglund, N. A. 1943. The effects of climate and grazing practices on short-grass prairie vegetation in southern Alberta and southwestern Saskatchewan. Technical Bulletin No. 46. Ottawa, Canada: Canadian Dominion, Department of Agriculture. 53 p. 
29. Collins, P. D.; Harper, K. T. 1982. Habitat types of the Curlew National Grassland, Idaho. Provo, UT: Brigham Young University, Department of Botany and Range Science. 46 p. Editorial draft. 
30. Collins, Thomas C. 1980. A report on the Moose Creek Fire of August, 1979. Unpublished report on file with: U.S. Department of Agriculture, Forest Service, Salmon National Forest, North Fork Ranger District, North Fork, ID. 27+ p. 
31. Coupland, R. T. 1992. Mixed prairie. In: Coupland, R. T., ed. Natural grasslands: Introduction and western hemisphere. Ecosystems of the World 8A. Amsterdam, Netherlands: Elsevier Science Publishers B. V.: 151-182. 
32. Coupland, Robert T. 1958. The effects of fluctuations in weather upon the grasslands of the Great Plains. Botanical Review. 24(5): 273-317. 
33. Coupland, Robert T. 1961. A reconsideration of grassland classification in the northern Great Plains of North America. Journal of Ecology. 49: 135-167. 
34. Coupland, Robert T.; Johnson, R. E. 1965. Rooting characteristics of native grassland species of Saskatchewan. Journal of Ecology. 53: 475-507. 
35. Coxson, Darwyn S.; Looney, John Henry H. 1986. Vegetation patterns within southern Alberta coulees. Canadian Journal of Botany. 64: 2464-2475. 
36. Cronquist, Arthur; Holmgren, Arthur H.; Holmgren, Noel H.; [and others]. 1977. Intermountain flora: Vascular plants of the Intermountain West, U.S.A. Vol. 6. The Monocotyledons. New York: Columbia University Press. 584 p. 
37. Currie, P. O.; Reichert, D. W.; Malechek, J. C.; Wallmo, O. C. 1977. Forage selection comparisons for mule deer and cattle under managed ponderosa pine. Journal of Range Management. 30(5): 352-356. 
38. Currie, Pat O.; Goodwin, D. L. 1966. Consumption of forages by black-tailed jackrabbits on salt-desert ranges of Utah. Journal of Wildlife Management. 30(2): 304-311. 
39. Daley, Richard Halbert. 1972. The native sand sage vegetation of eastern Colorado. Fort Collins, CO: Colorado State University. 62 p. Thesis. 
40. Darling, Andrea P.; Young, Steve A. 1984. The effects of native hay mulch on soil stabilization and introduction of native species on strip mined lands in southeastern Montana. In: Proceedings, 3rd biennial symposium on surface coal mine reclamation on the Great Plains; 1984 March 19-21; [Location unknown]. [Place of publication unknown]: [Publisher unknown]: 296-306. On file with: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, MT. 
41. Daubenmire, R. 1968. Ecology of fire in grasslands. In: Cragg, J. B., ed. Advances in ecological research. Vol. 5. New York: Academic Press: 209-266. 
42. Daubenmire, Rexford F.; Daubenmire, Jean B. 1968. Forest vegetation of eastern Washington and northern Idaho. Technical Bulletin 60. Pullman, WA: Washington State University, Agricultural Experiment Station. 104 p. 
43. Daubenmire, Rexford. 1969. Structure and ecology of coniferous forests of the northern Rocky Mountains. In: Taber, Richard D., ed. Coniferous forests of the northern Rocky Mountains: Proceedings of the 1968 symposium; 1968 September 17-20; Missoula, MT. Missoula, MT: University of Montana Foundation, Center for Natural Resources: 25-41. 
44. Davenport Seed Corporation. 1997. Rainier Seed., Inc. [Catalog]. Davenport, WA: Davenport Seed Corporation. 20 p. 
45. Davis, Carl. 1975. A guide for determining potential herbage productivity of central Montana range areas and potential range areas. ***Final Draft. Gallatin National Forest; Long Range Planning. 54 p. 
46. Delafield, Hardin, Jr. 1997. Needle and thread grass and Indian ricegrass regeneration response to prescribed fire in sagebrush/grass vegetation type: Dinasaur National Monument, Iron Springs Bench. Dinosaur, CO: U.S. Department of the Interior, National Park Service, Dinosaur National Monumnet. 7 p. Unpublished internal report on file with: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Lab, Missoula, MT. 
47. Delaney, L.; Grismer, G.; Grilz, P. 1988. Erosion control, mulching to restore prairie on an abused slope. Restoration & Management Notes. 6(1): 37. 
48. Dietz, Donald R.; Nagy, Julius G. 1976. Mule deer nutrition and plant utilization. In: Workman; Low, eds. Mule deer decline in the West: A symposium; [Date of conference unknown]; [Location of conference unknown]. [Logan], UT: College of Natural Resources, Utah Agriculture Experiment Station: 71-78. 
49. Dix, Ralph L. 1960. The effects of burning on the mulch structure and species composition of grasslands in western North Dakota. Ecology. 41(1): 49-56. 
50. Dormaar, Johan F.; Adams, Barry W.; Willms, Walter D. 1997. Impacts of rotational grazing on mixed prairie soils and vegetation. Journal of Range Management. 50(6): 647-651. 
51. Dusek, Gary L. 1975. Range relations of mule deer and cattle in prairie habitat. Journal of Wildlife Management. 39(3): 605-616. 
52. Eddleman, Lee E. 1979. Regeneration strategies of mixed-prairie plants. In: Goodin, J. R.; Northington, D. K., eds. Arid land plant resources: Proceedings of the international arid lands conference on plant resources; 1979 July; Lubbock, TX. Lubbock, TX: Texas Tech University, International Center for Arid and Semi-Arid Land Studies: 684-698. 
53. Ellison, Lincoln; Woolfolk, E. J. 1937. Effects of drought on vegetation near Miles City, Montana. Ecology. 18(3): 329-336. 
54. Erhard, Dean H. 1979. Plant communities and habitat types in the Lava Beds National Monument, California. Corvallis, OR: Oregon State University. 173 p. Thesis. 
55. Eyre, F. H., ed. 1980. Forest cover types of the United States and Canada. Washington, DC: Society of American Foresters. 148 p. 
56. Forde, Jon D.; Sloan, Norman F.; Shown, Douglas A. 1984. Grassland habitat management using prescribed burning in Wind Cave National Park, South Dakota. Prairie Naturalist. 16(3): 97-110. 
57. Foxx, Teralene S.; Tierney, Gail D. 1987. Rooting patterns in the pinyon-juniper woodland. In: Everett, Richard L., compiler. Proceedings--pinyon-juniper conference; 1986 January 13-16; Reno, NV. Gen. Tech. Rep. INT-215. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 69-79. 
58. Frederick, B. A.; Klein, D. A. 1994. Nitrogen effects on rhizosphere processes of range grasses from different successional seres. Plant and Soil. 161(2): 241-250. 
59. Freeman, D. Carl; Emlen, John M. 1995. Assessment of interspecific interactions in plant communities: an illustration from the cold desert saltbush grasslands of North America. Journal of Arid Environments. 31(2): 179-198. 
60. French, N. R. 1978. Reexamination of permanent vegetation plots on the Idaho National Engineering Laboratory Site. In: Markham, O. D., ed. Ecological studies on the Idaho National Engineering Laboratory Site: 1978 Progress Report. IDO-12087. Idaho Falls, ID: U.S. Department of Energy, Environmental Sciences Branch, Radiological and Environmental Sciences Lab: 167-170. 
61. Fudge, J. F.; Fraps, G. S. 1945. The chemical composition of grasses of northwestern Texas as related to soils and to requirements for range cattle. Bulletin No. 669. [Place of pulication unknown]: Texas Agricultural Experiment Station. 56 p. 
62. Garrison, George A.; Bjugstad, Ardell J.; Duncan, Don A.; [and others]. 1977. Vegetation and environmental features of forest and range ecosystems. Agric. Handb. 475. Washington, DC: U.S. Department of Agriculture, Forest Service. 68 p. 
63. Gartner, F. R. 1986. The many faces of South Dakota rangelands: description and classification. In: Clambey, Gary K.; Pemble, Richard H., eds. The prairie: past, present and future: Proceedings, 9th North American prairie conference; 1984 July 29 - August 1; Moorhead, MN. Fargo, ND: Tri-College University Center for Environmental Studies: 81-85. 
64. Gartner, F. R.; Lindsey, J. R. 1986. Vegetation responses to spring burning in western South Dakota. In: Clambey, Gary K.; Pemble, Richard H., eds. The prairie: past, present and future: Proceedings, 9th North American prairie conference; 1984 July 29 - August 1; Moorhead, MN. Fargo, ND: Tri-College University Center for Environmental Studies: 143-146. 
65. Goetz, Harold. 1963. Growth and development of native range plants in the mixed grass prairie of western North Dakota. Fargo, ND: North Dakota State University. 141 p. Thesis. 
66. Great Plains Flora Association. 1986. Flora of the Great Plains. Lawrence, KS: University Press of Kansas. 1392 p. 
67. Green, Lisle R.; Sharp, Lee A.; Cook, C. Wayne; Harris, Lorin E. 1951. Utilization of winter range forage by sheep. Journal of Range Management. 4: 233-241. 
68. Grosz, Kevin Lee. 1988. Sharp-tailed grouse nesting and brood rearing habitat in grazed and nongrazed treatments in southcentral North Dakota. Fargo, ND: North Dakota State University. 72 p. M.S. thesis. 
69. Gullion, Gordon W. 1964. Contributions toward a flora of Nevada. No. 49: Wildlife uses of Nevada plants. CR-24-64. Beltsville, MD: U.S. Department of Agriculture, Agricultural Research Service, National Arboretum Crops Research Division. 170 p. 
70. Hallsten, Gregory P.; Skinner, Quentin D.; Beetle, Alan A. 1987. Grasses of Wyoming. 3rd ed. Research Journal 202. Laramie, WY: University of Wyoming, Agricultural Experiment Station. 432 p. 
71. Halvorson, Gary A.; Lang, Kent J. 1989. Revegetation of a salt water blowout site. Journal of Range Management. 42(1): 61-65. 
72. Hansen, Paul L.; Hoffman, George R. 1986. Selected habitat types of the Custer National Forest. In: Clambey, Gary K.; Pemble, Richard H., eds. The prairie: past, present and future: Proceedings of the ninth North American prairie conference; 1984 July 29 - August 1; Moorhead, MN. Fargo, ND: Tri-College University Center for Environmental Studies: 79-81. 
73. Hansen, Paul L.; Hoffman, George R. 1988. The vegetation of the Grand River/Cedar River, Sioux, and Ashland Districts of the Custer National Forest: a habitat type classification. Gen. Tech. Rep. RM-157. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 68 p. 
74. Hansen, Paul L.; Hoffman, George R.; Bjugstad, Ardell J. 1984. The vegetation of Theodore Roosevelt National Park, North Dakota: a habitat type classification. Gen. Tech. Rep. RM-113. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 35 p. 
75. Hansen, Richard M.; Gold, Ilyse K. 1977. Blacktail prairie dogs, desert cottontails and cattle trophic relations on shortgrass range. Journal of Range Management. 30(3): 210-214. 
76. Hanson, Herbert C. 1955. Characteristics of the Stipa comata-Bouteloua gracilis- Bouteloua curtipendula association in northern Colorado. Ecology. 36(2): 267-280; 1955. 
77. Hassan, M. A.; West, N. E. 1986. Dynamics of soil seed pools in burned and unburned sagebrush semi-deserts. Ecology. 67(1): 269-272. 
78. Hassell, Wendell G.; Barker, Reed E. 1985. Relationships and potential development of selected needlegrasses and ricegrasses for western North American rangelands. In: Carlson, Jack R.; McArthur, E. Durant, chairmen. Range plant improvement in western North America: Proceedings of a symposium at the annual meeting of the Society for Range Management; 1985 February 14; Salt Lake City, UT. Denver, CO: Society for Range Management: 14-19. 
79. Hickman, James C., ed. 1993. The Jepson manual: Higher plants of California. Berkeley, CA: University of California Press. 1400 p. 
80. Hitchcock, A. S. 1951. Manual of the grasses of the United States. Misc. Publ. No. 200. Washington, DC: U.S. Department of Agriculture, Agricultural Research Administration. 1051 p. [2nd edition revised by Agnes Chase in two volumes. New York: Dover Publications, Inc.]. 
81. Hobbs, N. Thompson; Baker, Dan L.; Ellis, James E.; Swift, David M. 1981. Composition and quality of elk winter diets in Colorado. Journal of Wildlife Management. 45(1): 156-171. 
82. Hoffman, G. R.; Hazlett, D. L. 1977. Effects of aqueous Artemisia extracts and volatile substances on germination of selected species. Journal of Range Management. 30(2): 134-137. 
83. Hubbard, William A. 1950. The climate, soils, and soil-plant relationships of an area in southwestern Saskatchewan. Scientific Agriculture. 30(8): 327-342. 
84. Jefferies, Ned W. 1965. Herbage production on a Gambel oak range in southwestern Colorado. Journal of Range Management. 18(4): 212-213. 
85. Johnson, James R.; Nichols, James T. 1970. Plants of South Dakota grasslands: A photographic study. Bull. 566. Brookings, SD: South Dakota State University, Agricultural Experiment Station. 163 p. 
86. Jones, Webster B. 1965. Response of major plant species to elk and cattle grazing in northwestern Wyoming. Journal of Range Management. 18: 218-220. 
87. Kartesz, John T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. Volume I--checklist. 2nd ed. Portland, OR: Timber Press. 622 p. 
88. Kaul, Robert P.; Keeler, Kathleen H. 1980. Effects of grazing and juniper-canopy closure on the prairie flora in Nebraska high-plains canyons. In: Kucera, Clair L., ed. Proceedings, 7th North American prairie conference; 1980 August 4-6; Springfield, MO. Columbia, MO: University of Missouri: 95-105. 
89. Kearney, Thomas H.; Peebles, Robert H.; Howell, John Thomas; McClintock, Elizabeth. 1960. Arizona flora. 2d ed. Berkeley, CA: University of California Press. 1085 p. 
90. Kirsch, Leo M.; Kruse, Arnold D. 1973. Prairie fires and wildlife. In: Proceedings, annual Tall Timbers fire ecology conference; 1972 June 8-9; Lubbock, TX. Number 12. Tallahassee, FL: Tall Timbers Research Station: 289-303. 
91. Kuchler, A. W. 1964. United States [Potential natural vegetation of the conterminous United States]. Special Publication No. 36. New York: American Geographical Society. 1:3,168,000; colored. 
92. Manske, Llewellyn Leo. 1980. Habitat, phenology and growth of selected sandhills range plants. Fargo, ND: North Dakota State University. 154 p. Dissertation. 
93. McCorquodale, Scott M. 1993. Winter foraging behavior of elk in the shrub-steppe of Washington. Journal of Wildlife Management. 57(4): 881-890. 
94. Meier, Gretchen; Weaver, T. 1997. Desirables and weeds for roadside management--a northern Rocky Mountain catalogue. Report No. RHWA/MT-97/8115. Final report: July 1994-December 1997. Helena, MT: State of Montana Department of Transportation, Research, Development, and Technology Transfer Program. 145 p. 
95. Melgoza, Graciela; Nowak, Robert S. 1991. Competition between cheatgrass and two native species after fire: implications from observations and measurements of root distribution. Journal of Range Management. 44(1): 27-33. 
96. Melgoza, Graciela; Nowak, Robert S.; Tausch, Robin J. 1990. Soil water exploitation after fire: competition between Bromus tectorum (cheatgrass) and two native species. Oecologia. 83(1): 7-13. 
97. Moomaw, James Curtis. 1956. Some effects of grazing and fire on vegetation in the Columbia Basin region, Washington. Pullman, WA: State College of Washington. 87 p. Dissertation. 
98. Morrison, Linda C.; DuBois, John D.; Kapustka, Lawrence A. 1986. The vegetational response of a Nebraska sandhills grassland to a naturally occurring fall burn. Prairie Naturalist. 18(3): 179-184. 
99. Moss, E. H. 1955. The vegetation of Alberta. Botanical Review. 21(9): 493-567. 
100. Mueggler, Walter F. 1988. Aspen community types of the Intermountain Region. Gen. Tech. Rep. INT-250. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 135 p. 
101. Mueller, J. M.; Weaver, J. E. 1942. Relative drought resistance of seedlings of dominant prairie grasses. Ecology. 23: 387-398. 
102. National Academy of Sciences. 1971. Atlas of nutritional data on United States and Canadian feeds. Washington, DC: National Academy of Sciences. 772 p. 
103. Nemick, Joseph J. 1987. Sharp-tailed grouse management and ecology in Wyoming. In: Fisser, Herbert G., ed. Wyoming shrublands: Proceedings, 16th Wyoming shrub ecology workshop; 1987 May 26-27; Sundance, WY. Laramie, WY: University of Wyoming, Department of Range Management, Wyoming Shrub Ecology Workshop: 45-47. 
104. Pearson, L. C. 1964. Effect of harvest date on recovery of range grasses and shrubs. Agronomy Journal. 56: 80-82. 
105. Pechanec, Joseph F.; Stewart, George; Blaisdell, James P. 1954. Sagebrush burning good and bad. Farmers' Bulletin No. 1948. Washington, DC: U.S. Department of Agriculture. 34 p. 
106. Peden, Donald G. 1976. Botanical composition of bison diets on shortgrass plains. The American Midland Naturalist. 96(1): 225-229. 
107. Perez, Claudio J.; Waller, Steven S.; Moser, Lowell E.; [and others]. 1998. Seedbank characteristics of a Nebraska sandhills prairie. Journal of Range Management. 51(1): 52-62. 
108. Platou, K. A.; Tueller, P. T.; Leonard, S. G.; Miles, R. L. 1986. Soil properties associated with six common grasses of the Great Basin. Journal of Soil and Water Conservation. 41(6): 417-421. 
109. Ralphs, Michael H.; Schen, David C.; Busby, Fee. 1975. Prescribed burning--effective control of sagebrush and open juniper. Utah Science. 36(3): 94-98. 
110. Ralphs, Michael H.; Schen, David C.; Busby, Frank E. 1976. General considerations necessary in planning a prescribed burn. In: Use of prescribed burning in western woodland and range ecosystems: Proceedings of the symposium; 1976 March 18-19; Logan, UT. Logan, UT: Utah State University, Utah Agricultural Experiment Station: 49-53. 
111. Raunkiaer, C. 1934. The life forms of plants and statistical plant geography. Oxford: Clarendon Press. 632 p. 
112. Renner, F. G.; Allred, B. W. 1962. Classifying rangeland for conservation planning. Agric. Handb. 235. Washington, DC: U.S. Department of Agriculture, Soil Conservation Service. 48 p. 
113. Samuel, Marilyn J.; Hart, Richard H. 1994. Sixty-one years of secondary succession on rangelands of the Wyoming High Plains. Journal of Range Management. 47: 184-191. 
114. Schripsema, Janet R. 1978. Ecological changes on pine-grassland burned in spring, late spring and winter. Rapid City, SD: South Dakota State University. 99 p. Thesis. 
115. Schwarzkoph, Bill F. 1988. Reclaiming native prairie in southeastern Montana. In: Davis, Arnold; Stanford, Geoffrey, eds. The prairie: roots of our culture; foundation of our economy: Proceedings, 10th North American prairie conference; 1986 June 22-26; Denton, TX. Dallas, TX: Native Prairie Association of Texas: 09.06: 1-4. 
116. Shaw, A. F.; Cooper, C. S. 1973. The Interagency forage, conservation and wildlife handbook. Bozeman, MT: Montana State University, Extension Service. 205 p. 
117. Shiflet, Thomas N., ed. 1994. Rangeland cover types of the United States. Denver, CO: Society for Range Management. 152 p. 
118. Shown, Douglas A. 1982. The effects of prescribed burning on bird and small mammal communities in the grasslands of Wind Cave National Park. Houghton, MI: Michigan Technological University. 94 p. Thesis. 
119. Smoliak, S. 1965. A comparison of ungrazed and lightly grazed Stipa-Bouteloua prairie in southeastern Alberta. Canadian Journal of Plant Science. 45: 270-275. 
120. Stevens, Richard; Jorgensen, Kent R. 1994. Rangeland species germination through 25 and up to 40 years of warehouse storage. In: Monsen, Stephen B.; Kitchen, Stanley G., compilers. Proceedings--ecology and management of annual rangelands; 1992 May 18-22; Boise, ID. Gen. Tech. Rep. INT-GTR-313. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 257-265. 
121. Stickney, Peter F. 1989. Seral origin of species originating in northern Rocky Mountain forests. Unpublished draft on file at: U.S. Department of Agriculture, Forest Service, Intermountain Research Station, Fire Sciences Laboratory, Missoula, MT; RWU 4403 files. 10 p. 
122. U.S. Department of Agriculture, National Resource Conservation Service. (1999) The PLANTS database [Online]. (2000, January). National Plant Data Center (Producer). Available: http://plants.usda.gov/plants [2000, March 14]. 
123. U.S. Department of Agriculture, Soil Conservation Service. 1994. Plants of the U.S.--alphabetical listing. Washington, DC: U.S. Department of Agriculture, Soil Conservation Service. 954 p. 
124. Vaughan, Terry A. 1967. Food habits of the northern pocket gopher. The American Midland Naturalist. 77(1): 176-189. 
125. Vavra, M.; Rice, R. W.; Hansen, R. M.; Sims, P. L. 1977. Food habits of cattle on shortgrass range in northeastern Colorado. Journal of Range Management. 30(4): 261-263. 
126. Weaver, J. E. 1958. Summary and interpretation of underground development in natural grassland communities. Ecological Monographs. 28(1): 55-78. 
127. Weaver, J. E. 1968. Prairie plants and their environment: A fifty-year study in the Midwest. Lincoln, NE: University of Nebraska Press. 276 p. 
128. Weaver, J. E.; Albertson, F. W. 1956. Grasslands of the Great Plains. Lincoln, NE: Johnsen Publishing Company. 395 p. 
129. Weber, William A.; Wittmann, Ronald C. 1996. Colorado flora: eastern slope. 2nd ed. Nowot, CO: University Press of Colorado. 524 p. 
130. Welsh, Stanley L.; Atwood, N. Duane; Goodrich, Sherel; Higgins, Larry C., eds. 1987. A Utah flora. The Great Basin Naturalist Memoir No. 9. Provo, UT: Brigham Young University. 894 p. 
131. Whisenant, Steven G.; Uresk, Daniel W. 1989. Burning upland, mixed prairie in Badlands National Park. Prairie Naturalist. 21(4): 221-227. 
132. Wright, Henry A. 1967. Contrasting responses of squirreltail and needleandthread to herbage removal. Journal of Range Management. 20: 398-400. 
133. Wright, Henry A. 1970. A method to determine heat-caused mortality in bunchgrasses. Ecology. 51(4): 582-587. 
134. Wright, Henry A. 1971. Why squirreltail is more tolerant to burning than needle-and-thread. Journal of Range Management. 24: 277-284. 
135. Wright, Henry A. 1978. The effect of fire on vegetation in ponderosa pine forests: A state-of-the-art review. Lubbock, TX: Texas Tech University, Department of Range and Wildlife Management. 21 p. In cooperation with: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station. 
136. Wright, Henry A.; Britton, Carlton M. 1976. Fire effects on vegetation in western rangeland communities. In: Use of prescribed burning in western woodland and range ecosystems: Proceedings of the symposium; 1976 March 18-19; Logan, UT. Logan, UT: Utah State University, Agricultural Experiment Station: 35-41. 
137. Wright, Henry A.; Klemmedson, James O. 1965. Effect of fire on bunchgrasses of the sagebrush-grass region in southern Idaho. Ecology. 46(5): 680-688. 
138. Wright, Henry A.; Neuenschwander, Leon F.; Britton, Carlton M. 1979. The role and use of fire in sagebrush-grass and pinyon-juniper plant communities: A state-of-the-art review. Gen. Tech. Rep. INT-58. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station. 48 p. 
139. Young, Richard P. 1983. Fire as a vegetation management tool in rangelands of the Intermountain Region. In: Monsen, Stephen B.; Shaw, Nancy, compilers. Managing Intermountain rangelands--improvement of range and wildlife habitats: Proceedings; 1981 September 15-17; Twin Falls, ID; 1982 June 22-24; Elko, NV. Gen. Tech. Rep. INT-157. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station: 18-31.