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Sclerocactus wrightiae

L.D. Benson

Wright's Fishhook Cactus

G2Imperiled Found in 10 roadless areas NatureServe Explorer →
G2ImperiledGlobal Rank
Near threatenedIUCN
Very highThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.144121
Element CodePDCAC0J0A0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
IUCNNear threatened
CITESAppendix I
Endemicendemic to a single state or province
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderCaryophyllales
FamilyCactaceae
GenusSclerocactus
Other Common Names
Wright's fishhook cactus (EN)
Concept Reference
Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2024-05-20
Change Date1999-01-21
Edition Date2024-05-20
Edition AuthorsRoth, E., rev. B. Franklin (1996), rev. A. Frances (2013), rev. A. Treher (2016), rev. N. Ventrella (2024)
Threat ImpactVery high
Range Extent1000-5000 square km (about 400-2000 square miles)
Number of Occurrences21 - 80
Rank Reasons
Sclerocactus wrightiae is a perennial cactus that is endemic to east-central Utah, USA, occurring primarily on barren, alkaline soils of Mancos shale (and other geologic formations). This species is known from numerous locations in four Utah counties, but the number of individuals at each location is low, and populations are widely scattered throughout the range, with declines reported at many sites. Threats to this species are numerous and include livestock grazing, mineral and energy exploration and development, off-road vehicle use, drought, predation by native beetles and rodents, and illegal collection.
Range Extent Comments
Sclerocactus wrightiae occurs in western North America in the United States where it is endemic to east-central Utah in western Emery County, southeastern Sevier County, central Wayne County, and a small strip of Garfield County (USFWS 2022). According to the most recent five-year review of the species (USFWS 2022), the known range of this species is approximately 993,705 acres. Range extent was calculated at 3,680 square kilometers using data from the Utah Rare Plant Database (2021, UNHP 2021).
Occurrences Comments
By applying a 2 km separation distance to population location data from the Utah Rare Plant Database (2021), there are 69 estimated occurrences (UNHP 2021). Monitoring on federal lands indicates that many occurrences were still extant as of 2008 (USFWS 2008).
Threat Impact Comments
The USFWS (2022) considers livestock grazing impacts from trampling and uprooting of plants as a major threat to this species, and over 90 percent of of the Wright fishhook cactus range falls within grazing allotments. Off highway vehicle (OHV) use is also a concern for Sclerocactus wrightiae on Bureau of Land Management (BLM) lands; however OHV impacts have declined since the BLM improved regulations at the Factory Butte Special Management Area (USFWS 2022). Road maintenance activities such as grading may also cause impacts to cacti. With the exception of populations located in Capitol Reef National Park, the majority of the range of this species remains open to energy and mineral extraction and development and potential future solar development, which represents a significant threat to Wright's fishhook cactus. Additional threats include predation by the native beetle, Moneilema semipunctatum, and perhaps other beetles (Kass 2001b), as well as small mammal predation (UNHP 2021). Increased intensity and duration of drought due to climate change could severely impact this species, though this threat is difficult to quantify (USFWS 2022). Illegal collection of this cacti likely still occurs, although the scale of this threat is unknown.
Ecology & Habitat

Description

This cactus has a spherical or cylindrical shape and a pale green color. It grows up to 11 cm tall by 8 cm wide. There are several pale radial spines and a few hooked central spines with darkened tips on each areole. The radial spines are up to 2 cm long and the central spines may exceed 4 cm. The fragrant funnel- or bell-shaped flowers are white to pink in color and up to 4 cm long and wide.

Diagnostic Characteristics

Sclerocactus wrightiae displays considerable morphologic variation, presumably due to introgression with S. parviflorus; however, it can usually be recognized by its noticeably fragrant flowers with pink to white tepals, and magenta staminal filaments. Although S. wrightiae generally has smaller stems and flowers and shorter spines than S. parviflorus, there are many exceptions.

Habitat

Sclerocactus wrightiae occurs on barren, alkaline soils with widely scattered shrubs, perennial herbs, bunch grasses, or scattered pinyon and juniper at 1,280 to 2,320 m elevation on Cretaceous Mancos Shale and Dakota, Morrison, Carmel, Curtis, Summerville, and Entrada formations (Welsh et. al. 2015, USFWS 2022). Soils vary from clay to sandy silts to fine sands that may have a high gypsum content or contain little or no gypsum. Soil crusts are usually present and the ground surface is usually littered with sandstone or basalt gravels, cobbles, and boulders. Although the recovery plan (USFWS 1984) indicated the species occurred on a variety of soil formations, it appears the limiting factor is soil physiology with at least 3 of the following 4 requirements: 1) close proximity to fine textured, presumably saline and/or gypsiferous strata; 2) close proximity to a sand-forming geologic stratum that contributes to the substrate; 3) fine- or medium-sized gravels, pebbles, or fossil oyster shells in (and particularly littering) the surface of the soil; and 4) level to gently sloping terrain (USFWS 2008).

Reproduction

Wind, rainwater, and dispersal by ants and lagamorphs are all feasible dispersers of Sclerocactus wrightiae seeds (Lariviere et al. 2024). A 2024 study of the soil seed bank of this species found no seeds greater than 20 cm from the base of a cactus; however, seed bank densities beyond this distance likely exist but are too low to be detectable (Lariviere et al. 2024).
Terrestrial Habitats
Shrubland/chaparralSavannaGrassland/herbaceousDesertBarrens
Other Nations (1)
United StatesN2
ProvinceRankNative
UtahS2Yes
Threat Assessments
ThreatScopeSeverityTiming
2 - Agriculture & aquaculturePervasive - largeSerious or 31-70% pop. declineHigh (continuing)
2.3 - Livestock farming & ranchingPervasive - largeSerious or 31-70% pop. declineHigh (continuing)
3 - Energy production & miningPervasive - largeSerious or 31-70% pop. declineHigh (continuing)
3.1 - Oil & gas drillingLarge (31-70%)Serious or 31-70% pop. declineHigh (continuing)
3.2 - Mining & quarryingLarge (31-70%)Serious or 31-70% pop. declineHigh (continuing)
4 - Transportation & service corridorsLarge (31-70%)Moderate - slightHigh (continuing)
4.1 - Roads & railroadsLarge (31-70%)Moderate - slightHigh (continuing)
5 - Biological resource useLarge (31-70%)UnknownHigh (continuing)
5.2 - Gathering terrestrial plantsLarge (31-70%)UnknownHigh (continuing)
6 - Human intrusions & disturbanceLarge (31-70%)Moderate or 11-30% pop. declineHigh (continuing)
6.1 - Recreational activitiesLarge (31-70%)Moderate or 11-30% pop. declineHigh (continuing)
8 - Invasive & other problematic species, genes & diseasesPervasive (71-100%)Serious or 31-70% pop. declineHigh (continuing)
8.2 - Problematic native species/diseasesPervasive (71-100%)Serious or 31-70% pop. declineHigh (continuing)
11 - Climate change & severe weatherPervasive (71-100%)Serious - moderateHigh (continuing)
11.2 - DroughtsPervasive (71-100%)Serious - moderateHigh (continuing)

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Plant Characteristics
DurationPERENNIAL, Long-lived
Economic Value (Genus)No
Roadless Areas (10)
South Dakota (1)
AreaForestAcres
Indian CreekBuffalo Gap National Grassland24,666
Utah (9)
AreaForestAcres
Lookout PeakFishlake National Forest9,195
Lookout PeakFishlake National Forest9,195
Mcdonald BasinFishlake National Forest1,585
Mt. Johns Peak - Mt AliceFishlake National Forest12,469
Mt. Johns Peak - Mt AliceFishlake National Forest12,469
Muddy Creek - Nelson Mt.Manti-Lasal National Forest59,034
Solomon BasinFishlake National Forest19,963
Solomon BasinFishlake National Forest19,963
Thousand Lake MountainFishlake National Forest27,267
References (20)
  1. Alston, D. G., and V. J. Tepedino. 2000. Direct and Indirect Effects of Insecticides on Native Bees. In Grasshopper Integrated Pest Management User Handbook (Technical Bulletin No. 1809), edited by G.L. Cuningham and M.W. Sampson. Washington, DC: United States Department of Agriculture Animal and Plant Health Inspection Services.
  2. Anderson, J. 1985. Wright fishhook cactus recovery plan. Prepared in cooperation with the Wright Fishhook Cactus Recovery Committee. U.S. Fish and Wildlife Service, Denver, Colorado. 27 pp.
  3. Benson, L. 1982. The Cacti of the United States and Canada. Stanford University Press, Stanford, California. 1044 pp.
  4. Flora of North America Editorial Committee (FNA). 2003b. Flora of North America north of Mexico. Vol. 4, Magnoliophyta: Caryophyllidae, part 1. Oxford University Press, New York. xxiv + 559 pp.
  5. Heil, K.D., and J.M. Porter. 1994. Sclerocactus (Cactaceae): A revision. Haseltonia 2:20-46.
  6. Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
  7. Kass, R. 2001a. Demographic monitoring of Wright fishook cactus. In: Maschinski, Joyce; Holter, Louella, tech. eds. 2001. Southwestern rare and endangered plants: Proceedings of the Third Conference; 2000 September 25-28; Flagstaff, AZ. Proceedings RMRS-P-23. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 250 pp. Accessed online on 5/17/2011 at: http://www.fs.fed.us/rm/pubs/rmrs_p023.html
  8. Kass, R.J. 1990. Final report of habitat inventory of threatened, endangered, and candidate species in the San Rafael Swell, Utah. Prepared for: Bureau of Land Management, Utah State Office. Prepared by: Environmental Consulting, Springville, Utah. 87 pp.
  9. Kass, R.J., 2001b. Mortality of the endangered Wright fishhook cactus (<i>Sclerocactus wrightiae</i>) by an Opuntia-borer beetle (Cerambycidae: <i>Moneilema semipunctatum</i>). <i>Western North American Naturalist</i>, <i>61</i>(4), pp. 495-497.
  10. Lariviere, D., Anderson, V., Johnson, R. and Larsen, R. 2024. What Is in the Bank? Assessing Persistent Soil Seed Bank Density of <i>Sclerocactus wrightiae</i> (Cactaceae). <i>Diversity</i>, <i>16</i>(3), p.133.
  11. Neese, E. 1987. Final report: Habitat inventory for Sclerocactus wrightiae and other associated sensitive species. 2 volumes. Prepared for: Bureau of Land Management, Richfield District. Prepared by Neese Investigations, Salt Lake City, Utah.
  12. Tepedino, V. J., T. L. Griswold, and W. R. Bowlin. 2010. Reproductive biology, hybridization and flower visitors of the rare<i> Sclerocactus </i>taxa in Utah's Uinatah Basin. Western North American Naturalist 70(3): 377-386.
  13. U.S. Fish and Wildlife Service (USFWS). 1985. Wright fishhook cactus recovery plan. Prepared in cooperation with the Wright Fishhook Cactus Recovery Committee. U.S. Fish and Wildlife Service, Denver, Colorado. 27 pp.
  14. U.S. Fish and Wildlife Service (USFWS). 2008. Wright fishhook cactus (<i>Sclerocactus wrightiae</i> L. Benson) 5-year review: Summary and evaluation. U.S. Fish and Wildlife Service, West Valley City, Utah. 24 pp.
  15. U.S. Fish and Wildlife Service (USFWS). 2022. 5-Year Review Short Form, Wright fishhook cactus (<i>Sclerocactus wrightiae</i>). U.S. Fish and Wildlife Service, Utah Ecological Services Field Office, West Valley City, Utah. 17 pp.
  16. Utah Natural Heritage Program. 2021. Utah Rare Plant Database. (Accessed 2021).
  17. Utah Natural Heritage Program (UNHP). 2021. Element Subnational Ranking Form: <i>Sclerocactus wrightiae</i> in Biotics 5 database. NatureServe, Arlington, Virginia (accessed 2024).
  18. Welsh, S.L. 1979. Illustrated manual of proposed endangered and threatened plants of Utah. Brigham Young Univ., Provo, UT. 318 pp.
  19. Welsh, S.L., N.D. Atwood, S. Goodrich, and L.C. Higgins (eds.) 1993. A Utah flora. 2nd edition. Brigham Young Univ., Provo, Utah. 986 pp.
  20. Welsh, S.L., N.D. Atwood, S. Goodrich, and L.C. Higgins. (Eds). 2015. A Utah flora, fifth edition, revised 2015. Monte L. Bean Life Science Museum, Provo, Utah. 987 pp.