Regularity: Regularly occurring
Regularity: Regularly occurring
Global Range: It occurs in the U.S. in California, Nevada, Utah, Arizona, Colorado, New Mexico, Texas, Wyoming, Oklahoma; in Canada in Alberta and Saskatchewan; and likely in Mexico.
Plains pricklypear grows in the northern and southern Great Plains, the shrub- and woodlands of the Great Basin, the eastern Sierra Nevada, the borders of the Rocky Mountain forest regions, and the northern Chihuahuan Desert. It occurs from British Columbia to Manitoba southward through the Dakotas and Missouri to Texas and every state westward [6,30,42]. A distributional map of plains pricklypear is available on the PLANTS database. Distribution of infrataxa is as follows :
Opuntia polyacantha var. arenaria - in sandy soils near the Rio Grande of southeastern New Mexico, extreme western Texas, and northern Chihuahua
Opuntia polyacantha var. erinacea - Arizona
Opuntia polyacantha var. hysricina - eastern Utah and western Colorado
Opuntia polyacantha var. nicholii - Arizona and New Mexico
Opuntia polyacantha. var. polyacantha - Alberta and Saskatchewan south to western Texas, New Mexico, and southeastern Utah
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 :
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
16 Upper Missouri Basin and Broken Lands
Occurrence in North America
Plains pricklypear is a perennial, typically reaching 4 to 12 inches (10-30 cm) in height and rarely growing more than 16 inches (40 cm) tall . The glabrous, flattened stems are 2 to 4 inches (5-12 cm) broad, 2 to 5 inches (5-13 cm) long, and about 0.4 inches (1 cm) thick. Spines of these stems are only slightly barbed. The species tends to form clumps or mats that extend several yards in diameter [6,42]. Mats up to 12 feet (3.7 m) in width and 30 feet (9.15 m) long were observed in the Great Plains .
The fruits are dry at maturity and are covered with barbed spines. Fruits develop on stem lobes. An examination of 550 randomly selected branches revealed fruit on 32% of the stem lobes, varying from none to 5 fruits per lobe. The most fruit is produced on stem branches that are 6 to 8 years old. The number of seeds varies from none to more than 70 per fruit . Seeds are flat, and about 1.5 to 3.5 mm thick .
Plains pricklypear has a shallow, laterally extensive root system that takes advantage of rainfall as scant as 2.5 mm. Its high water retention capability in aboveground tissues allows it to survive drought. A clump 1 foot (0.3 m) in diameter may have a root system 4 to 6 feet (1.2-1.8 m) in diameter [17,22,71,97].
Opuntia plants usually live less than 20 years, but vegetative propagation can ensure a very long life span for the clonal colony .
Habitat and Ecology
Comments: Sandy soils of flats, washes, cayonsides, and hillsides in the desert, woodlands, plains.
Plains pricklypear occurs on dry sites in 22 central and western states and provinces. It is common in the Great Plains, Great Basin, and Southwest [,6,45]. Plains pricklypear occurs both on grazed ranges and in areas not used by livestock [38,97]. It occurs in disturbed roadside areas  and in old, relict, pre-agricultural plant communities [3,25]. It is found on clay loam and sandy loam soils but is infrequent on sand dunes. In grasslands, pricklypear does not occur in areas characterized by abundant soil moisture, such as swales and depressions. Its frequency decreases in wet years. Precipitation is a primary determinant of the distribution and abundance of plains pricklypear [76,97].
Plains pricklypear was classified in a Utah salt-gradient study as having a low tolerance to salt , but a survey of saline areas (visible salt crystals on the soil surface) in southern Alberta and Saskatchewan revealed that plains pricklypear was present on more than 11% of the sites .
Throughout its range, plains pricklypear occurs from as low as 1,000 feet (300 m) in the Great Plains  to at least as high as 8,000 feet (1,600 m) in the southern Great Basin .
Elevations reported in the literature are as follows:
4,300 to 7,500 feet (1,310-2,285 m) in Colorado [25,40]
2,250 to 5,700 feet (685-1,735 m) in Montana [61,83]
4,920 to 6,560 feet (1,500-2,000 m) in Utah 
1,000 to 5,000 feet (300-1,525 m) in the northern Great Plains 
1,000 to 8,000 feet (300-2,440 m) in the southern Great Plains [6,83]
Key Plant Community Associations
In the Great Plains of southern Alberta and Saskatchewan, the western Dakotas, and eastern Montana, Wyoming and Colorado, common associated grasses include blue grama (Bouteloua gracilis), western wheatgrass (Pascopyrum smithii), thickspike wheatgrass (Elymus lanceolatus), green needlegrass (Nassella viridula), needle-and-thread grass (Hesperostipa comata), buffalo grass (Buchloe dactyloides), prairie junegrass (Koeleria macrantha), Prairie sandreed (Calamovilfa longifolia), Sandberg bluegrass (Poa secunda), and threadleaf sedge (Carex filifolia). Associated shrubs and forbs may include big sagebrush (Artemisia tridentata), plains silver sagebrush (A. cana ssp. cana), fringed sagewort (A. frigida), rubber rabbitbrush (Chrysothamnus nauseosus), black greasewood (Sarcobatus vermiculatus), broom snakeweed (Gutierrezia sarothrae), shadscale (Atriplex confertifolia), Gardner's saltbush (A. gardneri), fourwing saltbush (A. canescens), winterfat (Krascheninnikovia lanata), and little clubmoss (Selaginella densa). Plains pricklypear occurs infrequently in the understory of open stands of ponderosa pine (Pinus ponderosa) [4,19,40,43,44,57,61,79,83].
In the cold desert grasslands and shrublands of the northern interior, including southern British Columbia, eastern Washington and Oregon, Idaho, and western Montana, plains pricklypear occurs with blue grama, western wheatgrass, thickspike wheatgrass, green needlegrass, needle-and-thread grass, Sandberg bluegrass, prairie junegrass, threadleaf sedge, bluebunch wheatgrass (Pseudoroegneria spicata), and Idaho fescue (Festuca idahoensis). Common associated shrubs are big sagebrush, fringed sagewort, gray low sagebrush (A. arbuscula spp. arbuscula), rubber rabbitbrush, green rabbitbrush (C. viscidiflorus), gray horsebrush (Tetradymia canescens), and broom snakeweed. Exotics include cheatgrass (Bromus tectorum) and spotted knapweed (Centaurea maculosa) [,49,60,66,72,79,83]. A bluebunch wheatgrass/plains prickly pear habitat type has been described for west-central Idaho [25,95,96].
In montane Utah, Nevada, and western Colorado, common plant associates are Colorado pinyon (Pinus edulis), Utah juniper (Juniperus osteosperma), true mountain-mahogany (Cercocarpus montanus), Gambel oak (Quercus gambelii), Utah serviceberry (Amelanchier utahensis), big sagebrush, black sagebrush (A. nova), budsage (A. spinescens), spiny hopsage (Grayia spinosa), shadscale, winterfat, Gardner's saltbush, green rabbitbrush, Hood's phlox (Phlox hoodii), and white sage (Kochia americana). Grasses include Indian ricegrass (Achnatherum hymenoides), bottlebrush squirreltail (Elymus elymoides), saline wildrye (Leymus salinus), and mutton grass (Poa fendleriana) [3,25,31,78].
In the southern Great Plains region of northern Texas, western Oklahoma, and eastern New Mexico, common plant associates include blue grama, buffalo grass, western wheatgrass, threeawn (Aristida spp.), lovegrass (Eragrostis spp.), sideoats grama (Bouteloua curtipendula), tobosa (Pleuraphis mutica), galleta (P. jamesii), and vine mesquite (Panicum obtusum). Dominant woody plants are broom snakeweed, sand sagebrush (A. filifolia), sand shinnery oak (Quercus havardii), cholla (Opuntia imbricata), soapweed yucca (Yucca glauca), and mesquite (Prosopis glandulosa) [28,83].
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: cover, shrub
SRM (RANGELAND) COVER TYPES :
101 Bluebunch wheatgrass
104 Antelope bitterbrush-bluebunch wheatgrass
105 Antelope bitterbrush-Idaho fescue
107 Western juniper/big sagebrush/bluebunch wheatgrass
301 Bluebunch wheatgrass-blue grama
302 Bluebunch wheatgrass-Sandberg bluegrass
303 Bluebunch wheatgrass-western wheatgrass
314 Big sagebrush-bluebunch wheatgrass
315 Big sagebrush-Idaho fescue
316 Big sagebrush-rough-fescue
317 Bitterbrush-bluebunch wheatgrass
318 Bitterbrush-Idaho fescue
319 Bitterbrush-rough fescue
323 Shrubby cinquefoil-rough fescue
324 Threetip sagebrush-Idaho fescue
401 Basin big sagebrush
402 Mountain big sagebrush
403 Wyoming big sagebrush
405 Black sagebrush
408 Other sagebrush types
412 Juniper-pinyon woodland
413 Gambel oak
414 Salt desert shrub
415 Curlleaf mountain-mahogany
416 True mountain-mahogany
503 Arizona chaparral
504 Juniper-pinyon pine woodland
505 Grama-tobosa shrub
507 Palo verde-cactus
509 Transition between oak-juniper woodland and mahogany-oak association
604 Bluestem-grama prairie
605 Sandsage prairie
611 Blue grama-buffalo grass
613 Fescue grassland
614 Crested wheatgrass
701 Alkali sacaton-tobosagrass
702 Black grama-alkali sacaton
703 Black grama-sideoats grama
704 Blue grama-western wheatgrass
705 Blue grama-galleta
706 Blue grama-sideoats grama
707 Blue grama-sideoats grama-black grama
712 Galleta-alkali sacaton
715 Grama-buffalo grass
727 Mesquite-buffalo grass
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 :
220 Rocky Mountain juniper
237 Interior ponderosa pine
238 Western juniper
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:
K011 Western ponderosa forest
K016 Eastern ponderosa forest
K017 Black Hills pine forest
K023 Juniper-pinyon woodland
K024 Juniper steppe woodlands
K031 Oak-juniper woodlands
K037 Mountain-mahogany-oak scrub
K038 Great Basin sagebrush
K043 Paloverde-cactus shrub
K053 Grama-galleta steppe
K054 Grama-tobosa prairie
K055 Sagebrush steppe
K056 Wheatgrass-needlegrass shrubsteppe
K057 Galleta-threeawn shrubsteppe
K058 Grama-tobosa shrubsteppe
K059 Trans-Pecos shrub savanna
K060 Mesquite savanna
K063 Foothills prairie
K065 Grama-buffalo grass
K068 Wheatgrass-grama-buffalo grass
K070 Sandsage-bluestem prairie
K085 Mesquite-buffalo grass
K088 Fayette prairie
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
FRES30 Desert shrub
FRES32 Texas savanna
FRES33 Southwestern shrubsteppe
FRES34 Chaparral-mountain shrub
FRES36 Mountain grasslands
FRES38 Plains grasslands
FRES40 Desert grasslands
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 81 to >300
Comments: 150+ EO's (Benson).
Fire Management Considerations
Frequent fire reduces populations of low-growing Opuntia species like plains pricklypear . Plants that survive in unburned refugia provide parents for regenerating burned areas. Observations of 1,665 plants from 19 succulent species on burned areas Arizona showed that 13% were in unburned refugia ; the spatial extent of the refugia was not described.
Fire has been used as a tool to increase the edibility of plains pricklypear and related species for livestock by burning off spines [32,84]. Wildlife consumption of burned plains pricklypear is also a consideration. In southern Alberta, pronghorn were attracted to burned areas to graze on plains pricklypear when spines were singed off green plants [19,88].
Although prescribed burning may effectively control plains pricklypear in some cases, in dry years desirable forage is lost [105,106]. In a 1965 Wyoming study, burning was among 4 treatments tested for controlling plains pricklypear. The other 3 methods were chemical, bulldozer blading over frozen ground, and beating with a tractor attachment. Burning was found to be unsatisfactory because, though cactus kill was estimated to be 70%, an unacceptable amount of preferred vegetation was damaged. At that time, the most successful method was thought to be blading, despite vegetation and soil damage .
Plant Response to Fire
The succulent stems of pricklypear species are not combustible and without sufficient fuel may suffer little damage from fire . However, it is reported that a related species, brownspine pricklypear (O. phaecantha), is easily killed by fire if the plant's height is less than 1 foot (0.3 m) . In west Texas, Heirman and Wright  also reported that brownspine pricklypear less than 2 feet (0.61 m) tall were easily killed by fire because flames readily engulfed the plants. Plains pricklypear postfire mortality may be delayed for 3 or more years. Secondary effects of fire include insect infestation of weakened plants and increased grazing pressure when spines are burned off [,13,14,77,101,105,107]. Studies in Texas showed that the cactus bug and the blue cactus borer prefer burned cactus pads to unburned pads [20,80,85,101]. This preference may increase pricklypear mortality after burning . In Wyoming, Smith and others  attributed mortality of plains pricklypear to dehydration following the burn rather than from fire-caused heat damage.
Brownspine pricklypear experienced high die-off following low-severity fire in Texas. Initial mortality was 20%. Insects entered surviving plants through fire-scarred tissue, spreading bacterial and fungal infections. New sprouts appeared within a few weeks following the fire, but many sprouting plants lost their vascular connection to the root because of insect damage and decay. By the end of the 3rd year, mortality exceeded 70%. Most plants surviving through postfire year 3 had sprouted from the root crown. The authors observed that mortality of both burned and unburned plants of brownspine pricklypear increased during years of below average precipitation .
Immediate Effect of Fire
Moderate or even low-severity fires can top-kill pricklypear species [7,93,99,106]. Aboveground tissues of Opuntia spp. are easily killed by fire, but some fleshy stem segments usually survive low- to moderate-severity fire and resume growth, even when burned off the parent plant [7,46,49,93,106]. Prickly-pears are vulnerable to mortality from heat generated by fires as well as by actual burning . Hotter fires probably lead to higher mortality, but data are needed [46,93].
Geophyte, growing points deep in soil
Plains pricklypear plants are vulnerable to fire [49,93,106]. Plants regenerate by sprouting from the root crown, by layering of unburned or partially burned stem pieces that contact soil, and from seedling establishment [1,13,56,93,97].
Many succulents, including plains pricklypear, live in fire-prone habitats with fire frequencies ranging from 1 to 3 years (Canadian prairies), to more than 250 years (Sonoran Desert). Succulent mortality after a fire is often greater than 50%, but rarely total. Authors speculate that increased fire severity causes increased succulent mortality, but data are lacking [46,93].
FIRE REGIMES for plant communities and ecosystems in which plains pricklypear is likely to occur are summarized below. For further information regarding FIRE REGIMES and fire ecology of communities and ecosystems where plains pricklypear 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)|
|bluestem prairie||Andropogon gerardii var. gerardii-Schizachyrium scoparium||12,54]|
|sagebrush steppe||Artemisia tridentata/Pseudoroegneria spicata||20-70 |
|basin big sagebrush||A. t. var. tridentata||12-43 |
|Wyoming big sagebrush||A. t. var. wyomingensis||10-70 (40)** [30,108]|
|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. gracilis-Hesperostipa comata-Pascopyrum smithii|
|blue grama-buffalo grass||B. gracilis-Buchloe dactyloides|
|grama-galleta steppe||Bouteloua gracilis-Pleuraphis jamesii|
|blue grama-tobosa prairie||B. gracilis-Pleuraphis mutica|
|paloverde-cactus shrub||Cercidium microphyllum/Opuntia spp.||12]|
|curlleaf mountain-mahogany*||Cercocarpus ledifolius||13-1000 [2,82]|
|mountain-mahogany-Gambel oak scrub||C. l.-Quercus gambelii|
|western juniper||Juniperus occidentalis||20-70|
|wheatgrass plains grasslands||Pascopyrum smithii|
|Mexican pinyon||P. cembroides||20-70 [65,91]|
|Rocky Mountain ponderosa pine*||P. ponderosa var. scopulorum||2-10|
|galleta-threeawn shrubsteppe||Pleuraphis jamesii-Aristida purpurea|
|mesquite-buffalo grass||P. g.-Buchloe dactyloides|
|Texas savanna||P. g. var. glandulosa|
|oak-juniper woodland (Southwest)||Quercus-Juniperus spp.|
|little bluestem-grama prairie||Schizachyrium scoparium-Bouteloua spp.||12]|
More info for the terms: climax, cover
Although plains pricklypear is present and often abundant in climax or late-successional communities throughout its range [3,25,37,103], it is often regarded a disturbance-adapted, early seral species . It increases in number in response to disturbances such as drought , grazing pressure , and severe hailstorms . Plains pricklypear cover decreases as precipitation normalizes following drought [45,97,103].
Plains pricklypear reproduces by seeds, layering, and sprouting from segments mechanically separated from the parent plant. Stem die-back in mature clumps can separate the plant into several individuals [56,97]. Detached stems buried in soil or litter may grow horizontally before sprouting [6,38,62,71,97,103]. Root sprouting has been documented in diploid populations of Opuntia polyacantha var. polyacantha in New Mexico [38,70]. Root sprouting may occur in other Opuntia polyacantha populations and infrataxa, but is poorly documented in the literature and in herbaria specimens .
Following a severe July hailstorm in northeastern Colorado, researchers quantified the number of plants that established from the many broken and scattered stem segments. In a pasture with an original plains pricklypear ground cover of 1.2%, the hail detached an estimated 1,660 segments/acre (4,100 segments/ha). In another pasture that had 3.3% plains pricklypear ground cover, 7,700 segments/acre (19,100 segments/ha) were detached by the storm. By August of the following year, 1,400 and 2,400 of the segments had rooted, respectively, in the 2 pastures .
Seeds of plains pricklypear fall near the parent plant or are dispersed by mammals that consume the fruits. They are also dispersed when barbs on the fruits or lobes attach to a passing large mammal [45,48,93,97,103,104]. Information on seed longevity was not found.
Seedling growth was measured for 3 years in 22 field plots in northeastern Colorado. By the end of the 3rd growing season plains pricklypear seedlings were only 2.5 to 3 inches (6-8 cm) in length. The diameter of well-developed clumps may increase 3 inches (8 cm) annually. Plains pricklypear clusters 3 feet (0.9 m) in diameter may take as much as 15 years to develop .
Growth Form (according to Raunkiær Life-form classification)
More info for the term: stem succulent
RAUNKIAER  LIFE FORM:
Life History and Behavior
More info for the term: phenology
|Floral buds developing||May|
Plains pricklypear showed a decline in carbohydrate reserves throughout winter quiescence, regreening of pads, and flowering, with a low point reached at the end of flowering. A maximum in the root carbohydrate reserves was found at fall quiescence .
In a southern Colorado study site, plains pricklypear bloomed for 21 to 28 days, beginning in late May. Individual flowers were open from 7-11 hours per day .
Flowering generally occurs from June to July in Montana and North Dakota .
Opuntia polyacantha as with other widespread Opuntias is known to reproduce both sexually and asexually, in addition to being self-dispersed and dispersed by animals that eat the fleshy fruits (Valiente-Banuet and Godinez-Alvarez 2002). This species is generally self-incompatible (Osborn et al. 1988).
Molecular Biology and Genetics
Statistics of barcoding coverage: Opuntia polyacantha
Public Records: 0
Specimens with Barcodes: 2
Species With Barcodes: 1
IUCN Red List Assessment
Red List Category
Red List Criteria
Opuntia polyacantha has a very wide range, is abundant, and there are no threats. Hence, it is listed as Least Concern.
National NatureServe Conservation Status
Rounded National Status Rank: N5 - Secure
Rounded National Status Rank: N5 - Secure
NatureServe Conservation Status
Rounded Global Status Rank: G5 - Secure
Reasons: Widespread throughout the southwestern United States.
Comments: Most cacti subject to horticultural collecting.
Land managers often view pricklypear cacti as a mixed blessing.
In some places dense stands of plains pricklypear compete with more desirable forage species and grass production is reduced. However, plains pricklypear grows in sites that will not support a high level of grass production (e.g. drought stricken and dusty, saline, or shallow and gravelly) [32,33,79,103]. Abundant plains pricklypear is sometimes cited as an indicator of poor range condition.
The presence of plains pricklypear can reduce both the production and
availability of forage . Hyde and others  reported forage
production doubled where mechanical beaters had been used to control
In the Colorado plains, Bement  measured percent cover of plains pricklypear after 25 years of light, moderate, and heavy cattle grazing and observed little effect on the abundance of plains pricklypear. He concluded, "The illusion that pricklypear abundance in this area is associated with heavier grazing is because the pricklypear in the more lightly-used pastures is camouflaged by the ungrazed grass." The cactus was more visible in the heavily grazed areas, thus appearing to be increasing as a result of grazing. He reported no increase in blue grama production after plains pricklypear control (hand clipping at the root crown) but did report that more forage was physically available for grazing.
Plains pricklypear is susceptible to damage by several insects,
including a moth (Melitara dentata), the blue cactus borer (Olycella
subumbrella), and the cactus bug (Chelinidea vittiger) [80,102]. These
insects are favored by moist conditions and can be an effective means of
natural control during wet periods . Both the cactus bug and the
blue cactus borer prefer burned cactus pads (stems) to unburned pads [58,80]. This preference may help to increase pricklypear
mortality after prescribed fire .
Because plains pricklypear colonies can survive and even increase during drought, they provide structural protection for more desirable species, usually grasses, to grow and produce seed. Where soil drifting and blowing occurs, the clusters of plants become microsites where topsoil, moisture and litter collect [5,45,103]. The ecology of pricklypears during the drought of the 1930's was closely observed by Weaver and Alberston , along with other Great Plains species. Their summary comments about the cacti are excerpted here:
"Interrelations of the short grasses to cactus, especially the opuntias which form large clumps, are of interest and importance. During the years of desiccation when the cactus increased so greatly, it furnished a haven for relict blue grama. It could not be grazed and consequently afforded oases for seed production. With the return of a more favorable environment for the enemies of cactus, their death began...Since the more drought resistant blue grama was often the sole survivor in or near the place where the cactus had grown, the ratio of this species to buffalo grass was often higher in soil formerly occupied by the cactus."
Relevance to Humans and Ecosystems
In Texas, northern bobwhite quail rely on plains pricklypear for cover while traveling and escape from predators. Many other small birds and mammals rely on pricklypear species for protective cover [33,59].
The palatability of plains pricklypear to livestock and wildlife is generally considered poor to fair, because spines deter grazing . When spines are singed off by wildfires not severe enough to destroy the plants, plains pricklypear becomes a desirable food source [19,88]. Cattle ranchers in the
southwestern U.S. burn plains pricklypear plants to remove spines and rendering them fit for livestock consumption [32,84].
Other uses and values
Many species of Opuntia pricklypear are used as food by humans [32,33,35,67]. Native Americans ate plains pricklypear fruit raw, dried, or cooked. Fruit was piled on the ground and stirred with branches, rolled or singed with hot coals to remove spines, then split and dried in the sun. The flesh of plains pricklypear was used as a binding agent in garment and weapon making. Ripe fruits were used for dye [15,24,36].
Prickly-pear in the genus Opuntia have been utilized as a forage substitute for grazing livestock in Texas and Mexico for at least a century. It is highly variable in nutrient content, depending on species or variety, age, and plant part. Most research indicates that Opuntia pricklypear are low in protein and phosphorus but high in energy, water, fiber, and ash
Singed plains pricklypear was evaluated as a cattle forage in Colorado. Plains pricklypear increased total dry matter consumption and weight gain in cattle. Chemical analyses indicated that digestibility of plains pricklypear was at least equal to that of alfalfa
(Medicago sativa) hay. Plains pricklypear contained about 40% more soluble carbohydrates than alfalfa
hay, but only about 3.4% digestible protein. The authors concluded that singed plains pricklypear was palatable and nutritious, but should be supplemented with protein .
Importance to Livestock and Wildlife
Plains pricklypear is an important seasonal food of the black-tailed prairie dog, composing up to 58% of its winter diet [10,16,27,53,90].
Pronghorn rely on plains pricklypear [4,92], notably after fire [19,88]. Fires burn the spines off the plants, providing a source of preferred forage.
Other animals reported to eat plains pricklypear include:
northern pocket gopher 
bushy-tailed woodrat 
Nuttall cottontail [50,60]
black-tailed jackrabbit 
white-tailed jackrabbit 
desert cottontail 
least chipmunk 
white-tailed deer [32,33]
collared peccary [33,59]
northern bobwhite 
Plains pricklypear is regarded as an important emergency forage for livestock. Although the moisture content of aboveground tissues of plains pricklypear is high, nutrient content is low [32,33].
Opuntia polyacantha is a common species of cactus known by the common names plains pricklypear, hairspine cactus, panhandle pricklypear, and starvation pricklypear. It is native to North America, where it is widespread in Western Canada, the Great Plains, the central and Western United States, and Chihuahua in northern Mexico.
Opuntia polyacantha grows up to 40 centimetres (16 in) tall. It forms low mats of pads which may be 2–3 metres (6.6–9.8 ft) wide. Its succulent green pads are oval or circular and reach 27 by 18 centimetres (10.6 by 7.1 in) wide. Its areoles are tipped with woolly brown fibers and glochids. Many of the areoles have spines which are quite variable in size and shape. They may be 0.4 to 18.5 centimetres (0.16 to 7.28 in) in length, stout or thin, straight or curling, and any of a variety of colors.
The flowers are 2.5 to 4 centimetres (0.98 to 1.57 in) long and may be yellow or magenta in color. The fruit is cylindrical, brownish, dry and spiny. The cactus reproduces by seed, by layering, and by resprouting from detached segments.
This pricklypear provides food for many types of animals. It provides over half the winter food for the black-tailed prairie dog in one area. Pronghorn deer eat it, especially after the spines are burned off in wildfires. Ranchers intentionally burn stands of the plant to make it palatable for livestock when little other food is available. It will also grow in waste areas where good forage will not take hold. In fact, an abundance of the cactus indicates land that is poor in quality.
- Johnson, K. A. 2000. Opuntia polyacantha. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Retrieved May 11, 2011.
- Opuntia polyacantha. USDA Plants Profile. Retrieved May 11, 2011.
- Opuntia polyacantha. The Nature Conservancy. Retrieved May 11, 2011.
- Opuntia polyacantha. Flora of North America. Retrieved May 11, 2011.
- University of Michigan - Dearborn: Native American Ethnobotany (Opuntia polyacantha)
Names and Taxonomy
Comments: Distinct taxon.
The fully documented scientific name of plains pricklypear is Opuntia
polyacantha Haw. (Cactaceae) [6,30,42,51,69]. Infrataxa are as follows
Opuntia polyacantha var. arenaria (Englm.) Parfitt
Opuntia polyacantha var. erinacea (Englm.) Parfitt
Opuntia polyacantha var. hysricina (Engelm.) Parfitt
Opuntia polyacantha var. nicholii (L. Benson) Parfitt
Opuntia polyacantha. var. polyacantha
Grizzlybear pricklypear (Opuntia × columbiana Griffiths) is a brittle
pricklypear × little pricklypear (O. fragilis) hybrid .