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SPECIES:  Hesperostipa spartea
Porcupinegrass. Wikimedia Commons image by Krista Lundgren, U.S. Fish & Wildlife Service.


SPECIES: Hesperostipa spartea
AUTHORSHIP AND CITATION: Walkup, Crystal J. 1991. Hesperostipa spartea. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: [].
Revisions: On 4 October 2018, the common name of this species was changed in FEIS from: porcupinegrass to: porcupine grass. Images were also added.
ABBREVIATION: HESSPA SYNONYMS: Stipa spartea Trin.[22,23] Stipa robusta Nutt. ex Trin. NRCS PLANT CODE: STSP2 COMMON NAMES: porcupinegrass big needlegrass short-awn porcupine grass western porcupine grass TAXONOMY: The currently accepted scientific name for porcupinegrass is Hesperostipa spartea (Trin.) Barkworth (Poaceae)[54]. LIFE FORM: Graminoid FEDERAL LEGAL STATUS: No special status OTHER STATUS: Porcupinegrass is considered rare in Ontario.


SPECIES: Hesperostipa spartea
GENERAL DISTRIBUTION: Porcupinegrass is found from British Columbia to Ontario, south through Montana, Wyoming, Colorado, and New Mexico, and east through most of the central states to Pennsylvania [46].
Distribution of porcupinegrass. Map courtesy of USDA, NRCS. 2018. The PLANTS Database. National Plant Data Team, Greensboro, NC. [2018, October 4] [46].
   FRES15  Oak - hickory
   FRES21  Ponderosa pine
   FRES29  Sagebrush
   FRES36  Mountain meadows
   FRES38  Plains grasslands
   FRES39  Prairie

     AZ  CO  IL  IN  IA  KS  MN  MO  MT  MI
     MN  NM  OH  OK  PA  SD  TX  WI  WY  AB
     BC  MB  NB  ON  SK

   10  Wyoming Basin
   12  Colorado Plateau
   13  Rocky Mountain Piedmont
   14  Great Plains
   15  Black Hills Uplift
   16  Upper Missouri Basin and Broken Lands

   K016  Eastern ponderosa forest
   K056  Wheatgrass - needlegrass shrubsteppe
   K063  Foothills prairie
   K064  Grama - needlegrass - wheatgrass
   K066  Wheatgrass - needlegrass
   K067  Wheatgrass - bluestem - needlegrass
   K068  Wheatgrass - grama - buffalograss
   K069  Bluestem - grama prairie
   K074  Bluestem prairie
   K081  Oak savanna

    14  Northern pin oak
    42  Bur oak
   110  Black oak
   236  Bur oak
   237  Interior ponderosa pine

In Indiana, porcupinegrass and little bluestem (Schizachyrium 
scoparium) are major components in dry sand prairies and black 
oak (Quercus velutinus) savannahs [6].  In Wisconsin, South Dakota, 
and Nebraska, it is codominant with little bluestem [8,28,45].

Porcupinegrass occurs as a dominant or subdominant in the following
community type (cts) classifications:

Area                          Classification       Authority

sw ND                         grassland cts        Whitman 1979 
sc ND: Central Grasslands     grassland cts        Lura and others 1988
       Research Station
   ND:  Woodworth Station        general veg. cts     Meyer 1985

Alberta:  Peace - Athabasca   general veg. cts     Dirschl and others
          Delta                                    1974


SPECIES: Hesperostipa spartea
IMPORTANCE TO LIVESTOCK AND WILDLIFE: Porcupinegrass is an important early season forage of good but not choice palatability for all classes of livestock. As the species matures the leaves become somewhat tough for sheep but are still grazed to some extent. The value of porcupinegrass as forage is relatively higher in the fall than in midsummer because it remains green after most grasses have dried [24]. PALATABILITY: Palatability varies with phenological development. Palatability is highest in the spring and early summer when plants are young and succulent. Porcupinegrass remains moderately palatable until the seedheads mature, at which time long, sharp awns may injure grazing livestock and render the plant less palatable [18,40]. The relish and degree of use shown by livestock and wildlife species for porcupinegrass in Montana and North Dakota has been rated as follows [12]: MT ND Cattle Fair Fair Sheep Fair Poor Horses Fair Fair Pronghorn ---- Poor Mule deer ---- Poor White-tailed deer ---- Poor Small nongame birds ---- Poor Upland game birds ---- Good NUTRITIONAL VALUE: The nutritional value of porcupinegrass during five major stages of growth are [26] (values are percentage of dry weight with the exception of carotene which is in mg/kg): Leaf Stage Heading Seed-ripe Cured Weathered Dry Matter 94.0 92.0 92.0 94.0 94.0 Protein 9.1 6.2 7.3 4.3 4.5 Crude Fat 3.4 3.2 4.2 4.3 3.5 Crude Fiber 28.0 34.0 29.0 31.0 32.0 Ash 7.0 5.6 6.6 8.2 8.0 Calcium 0.3 0.3 0.3 0.4 0.4 Phosphorus 0.1 0.1 0.1 0.1 0.1 Carotene 20.0 24.0 67.0 6.9 2.9 COVER VALUE: The degree to which porcupinegrass provides environmental protection during one or more seasons for wildlife species has been rated as follows [12]: ND Pronghorn Good Mule deer Good White-tailed deer Fair Small nongame birds Good Upland game birds Good Waterfowl Fair VALUE FOR REHABILITATION OF DISTURBED SITES: Trail restoration was conducted in Saskatoon, Saskatchewan, on old trails found on a steep (2:1), sandy, south-facing slope. Seeds found in prairie hay mulch (primarily needle and thread (Hesperostipa comata) and porcupinegrass) held down by jute mesh blankets successfully germinated and established new growth [10]. Porcupinegrass is difficult to establish by seed. Germination varies from 0 to 12 percent [21], and seeds are extremely difficult to clean, which reduces purity. Transplanting has been fairly successful but is very costly [37,41]. Porcupinegrass mulch seems to be the best choice for successful, low-cost establishment. OTHER USES AND VALUES: Native Americans of the Missouri River Region used the stiff awns to make hair brushes [17]. OTHER MANAGEMENT CONSIDERATIONS: Porcupinegrass decreases with overgrazing. Moderate to severe grazing pressure greatly reduces later growth and seed production [14,49]. Slight to light use removes standing litter, increasing growth of porcupinegrass [44]. Frequent early mowing (June or July) results in a decrease in cover of porcupinegrass, whereas delaying mowing until August may increase its cover [8,9]. Porcupinegrass does poorly under drought conditions but is able to recover once conditions have returned to normal. Seedling survival during simulated drought conditions ranged from 0 to 54 percent [36]. Porcupinegrass was listed among species which had high mortality during the 30's drought. Mortality was thought to result from the relatively shorter roots on these grasses. However, once drought conditions ended, porcupinegrass regained its original territory and spread widely [48].


SPECIES: Hesperostipa spartea
GENERAL BOTANICAL CHARACTERISTICS: Porcupinegrass is a native, perennial, cool-season bunchgrass. It is often confused with needle-and-thread grass, but its leaves are longer, generally less rolled, lighter in color, and considerably wider [18]. It may grow to a height of 4 feet (1.2 m) but generally reaches 1.5 to 3 feet (0.45-0.9 m). Flower stalks grow from 2 to 4 feet (0.6-1.2 m). Root systems of mature plants usually reach depths of about 4.5 feet (1.35 m), but occasionally extend to 6 feet (1.8 m). Numerous, profusely branched, smaller roots occupy the top 8 to 18 inches (20-46 cm) of soil, spreading horizontally or diagonally downward. The longer roots give rise to many laterals which divide into fine branches in deeper soil [47]. RAUNKIAER LIFE FORM: Cryptophyte Geophyte REGENERATION PROCESSES: Porcupinegrass reproduces sexually [12]. The seeds have a unique method of planting themselves. As the twisted awns expand and contract with variations in temperature and moisture, the seeds drill into the soil.
Porcupinegrass seed. Wikimedia Commons image by Paul Henjum.
Strong winds may transport seeds a considerable distance, especially
when awns are twisted together in clumps [42].  Animals also carry seeds
as the awns become trapped in their coats.

Porcupinegrass is found in prairies, foothills, and canyons at lower
elevations, often dominating dry, well-drained sites [14,45].  In
Colorado it is found from 5,300 to 7,500 feet (1,615 to 2,286 m) in dry
to moist habitats [12].  In Minnesota it is dominant on a sandy level
upland.  It also occurs on well-drained gentle slopes but is not
dominant [13].  In Nebraska it is found on high prairie, low prairie,
and disturbed areas, but is typically an upland species, generally
dominant on south and east slopes [8,42].  It mainly occurs on poorer
soil types throughout the northern Great Plains [40].

Porcupinegrass is a climax dominant on several sites in the Great
Plains [8,28,45].  It also occurs as a pioneer species, often
establishing on small disturbed or denuded areas, such as gopher mounds

Leaf growth of porcupinegrass begins in late March to early April in
western North Dakota [18].  Flowering occurs earliest in the eastern and
southern, and latest in the northern and western portion of its range
[33].  In Wyoming, North Dakota, and Nebraska flowering occurs from May
to June [12,42], and in Montana from June to August [12].

A study in western North Dakota recorded an 8-year average of the
significant phenological stages of porcupinegrass [18].

Initiation of   Head                  Seed       Seed      Leaves
Fruiting Stalk  Emergence  Anthesis   Maturity   Shatter   50-75% Dry

June 2          June 14    June 28    June 27    July 9    August 28


SPECIES: Hesperostipa spartea
FIRE ECOLOGY OR ADAPTATIONS: Porcupinegrass survives low to moderate severity fires due to carbohydrate reserves stored in an underground root crown. It lacks rhizomes, and the root system is relatively shallow. Severe fires can kill the root crown, but such fires are rare on grasslands [48]. Fire was an important ecological factor on prairies containing porcupine grass. In the absence of fire, tree encroachment was common, and the plant community often changed to forest within 30 years [3,50]. FIRE REGIMES: Find fire regime information for the plant communities in which this species may occur by entering the species name in the FEIS home page under "Find Fire Regimes". POSTFIRE REGENERATION STRATEGY: survivor species; on-site surviving root crown off-site colonizer; seed carried by animals or wind; postfire yr 1&2


SPECIES: Hesperostipa spartea
IMMEDIATE FIRE EFFECT ON PLANT: Aboveground portions of porcupinegrass are removed by fire. PLANT RESPONSE TO FIRE: Kruse and Higgins [29] reported porcupinegrass both increasing and decreasing following spring burns. Four studies reported favorable responses after spring burns which occurred from April 30 to May 26 [3,7,27,38], while four reported neutral or negative responses after burning between April 9 and May 8 [2,20,25,52]. Positive effects include increased seed production and flowering [3,38], an increase in total biomass [7], and an increase in cover [27]. Negative effects include a decrease in cover [2,25] and a reduction in culm production [20]. Porcupinegrass was listed as actively growing in one study [25], and growing season precipitation was lower than normal in another study [20], which may account for the negative responses. The majority of the studies provided insufficient information for direct comparison of the effects of burning in different seasons. A general statement about cool-season grasses is that they are harmed by late spring burns when actively growing. The four studies which gave results contradicting this did not report the phenological stage of porcupine grass prior to burning. DISCUSSION AND QUALIFICATION OF PLANT RESPONSE: Twenty-five years of annual burning decreased cover of western porcupine grass in east-central Alberta. No season or intensity of fire was given [1]. Annual spring burns (late April to early May) in two Minnesota studies favored porcupinegrass [43,50]. Burning was conducted to return the area to pre-settlement oak savannah woodlands [50], and to determine the effects of fire on an aspen-prairie ecotone [43]. Fall burning (October 3) reduced canopy coverage and seed production. The growth stage was not determined prior to the fire [3]. The Research Project Summary Seasonal fires in Saskatchewan rough fescue prairie provides information on prescribed fire use and postfire response of plains grassland community species, including porcupinegrass, that was not available when this species review was originally written. FIRE REGIMES:
Find fire regime information for the plant communities in which this species may occur by entering the species name in the FEIS home page under "Find Fire Regimes". FIRE MANAGEMENT CONSIDERATIONS: Due to the varied results under similar burning conditions, it is difficult to make accurate management recommendations.

References for species: Hesperostipa spartea

1. Anderson, Howard A. 1978. Annual burning and vegetation in the aspen parkland of east central Alberta. In: Dube, D. E., compiler. Fire ecology in resource management: Workshop proceedings; 1977 December 6-7; [Location unknown]. Information Report NOR-X-210. Edmonton, AB: Environment Canada; Canadian Forestry Service, Northern Forest Research Centre: 2:3. Abstract. [317]
2. Anderson, Roger C.; Leahy, Theresa; Dhillion, Shivcharn S. 1989. Numbers and biomass of selected insect groups on burned and unburned sand prairie. The American Midland Naturalist. 122: 151-162. [7912]
3. Bailey, Arthur W.; Anderson, Murray L. 1978. Prescribed burning of a Festuca-Stipa grassland. Journal of Range Management. 31: 446-449. [373]
4. Belcher, Joyce W.; Wilson, Scott D. 1989. Leafy spurge and the species composition of a mixed-grass prairie. Journal of Range Management. 42(2): 172-175. [6892]
5. 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. [434]
6. Betz, Robert F. 1978. The prairies of Indiana. In: Glenn-Lewin, David C.; Landers, Roger Q., Jr., eds. Proceedings, 5th Midwest prairie conference; 1976 August 22-24; Ames, IA. Ames, IA: Iowa State University: 25-31. [3292]
7. Blankespoor, Gilbert W. 1987. The effects of prescribed burning on a tall-grass prairie remnant in eastern South Dakota. Prairie Naturalist. 19(3): 177-188. [2757]
8. Boettcher, Judith F.; Bragg, Thomas B. 1989. Tallgrass prairie remnants of eastern Nebraska. In: Bragg, Thomas B.; Stubbendieck, James, eds. Prairie pioneers: ecology, history and culture: Proceedings, 11th North American prairie conference; 1988 August 7-11; Lincoln, NE. Lincoln, NE: University of Nebraska: 1-7. [14008]
9. Christiansen, Paul A. 1972. Management of Hayden Prairie: past, present and future. In: Zimmerman, James H., ed. Proceedings of the second Midwest prairie conference; 1970 September 18-20; Madison, WI. Madison, WI: University of Wisconsin Arboretum: 25-29. [2794]
10. Delaney, L.; Grismer, G.; Grilz, P. 1988. Erosion control, mulching to restore prairie on an abused slope. Restoration & Management Notes. 6(1): 37. [5475]
11. Dirschl, German J.; Dabbs, Don L.; Gentle, Garry C. 1974. Landscape classification and plant successional trends in the Peace-Athabasca Delta. Canadian Wildlife Service Report Series 30. Ottawa, ON: Canadian Wildlife Service. 33 p. [6177]
12. Dittberner, Phillip L.; Olson, Michael R. 1983. The plant information network (PIN) data base: Colorado, Montana, North Dakota, Utah, and Wyoming. FWS/OBS-83/86. Washington, DC: U.S. Department of the Interior, Fish and Wildlife Service. 786 p. [806]
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14. Ehrenreich, John H.; Aikman, John M. 1963. An ecological study of the effect on certain management practices on native prairie in Iowa. Ecological Monographs. 33(2): 113-130. [9]
15. Eyre, F. H., ed. 1980. Forest cover types of the United States and Canada. Washington, DC: Society of American Foresters. 148 p. [905]
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18. 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. [5661]
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23. Hitchcock, C. Leo; Cronquist, Arthur; Ownbey, Marion. 1969. Vascular plants of the Pacific Northwest. Part 1: Vascular cryptograms, gymnosperms, and monocotyledons. Seattle, WA: University of Washington Press. 914 p. [1169]
24. Hopper, T. H.; Nesbitt, L. L. 1930. The chemical composition of some North Dakota pasture and hay grasses. Bull. 236. Fargo, ND: North Dakota Agricultural College, Agricultural Experiment Station. 39 p. [3265]
25. Hover, Edward I.; Bragg, Thomas B. 1981. Effect of season of burning and mowing on an eastern Nebraska Stipa-Andropogon prairie. The American Midland Naturalist. 105(1): 13-18. [1199]
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29. Kruse, Arnold D.; Higgins, Kenneth F. 1990. Effects of prescribed fire upon wildlife habitat in northern mixed-grass prairie. In: Alexander, M. E.; Bisgrove, G. F., technical coordinators. The art and science of fire management: Proceedings, 1st Interior West Fire Council annual meeting and workshop; 1988 October 24-27; Kananaskis Village, AB. Inf. Rep. NOR-X-309. Edmonton, AB: Forestry Canada, Northwest Region, Northern Forestry Centre: 182-193. [14146]
30. Kuchler, A. W. 1964. Manual to accompany the map of potential vegetation of the conterminous United States. Special Publication No. 36. New York: American Geographical Society. 77 p. [1384]
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42. Steiger, T. L. 1930. Structure of prairie vegetation. Ecology. 11(1): 170-217. [3777]
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