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Agave utahensis

Engelm.

Utah Agave

G3Vulnerable Found in 14 roadless areas NatureServe Explorer →
G3VulnerableGlobal Rank
Least concernIUCN
HighThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.157120
Element CodePMAGA010S0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
IUCNLeast concern
Endemicendemic to a single nation
KingdomPlantae
PhylumAnthophyta
ClassMonocotyledoneae
OrderAsparagales
FamilyAsparagaceae
GenusAgave
Other Common Names
Utah agave (EN) Utah Century Plant (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.
Taxonomic Comments
According to the treatment in FNA (vol. 26, 2002), there are two subspecies in Agave utahensis, A. utahensis ssp. kaibabensis and A. utahensis ssp. utahanensis, with no varieties within subspecies kaibabensis, and three varieties within subspecies utahensis: (var. eborispina, var. nevadensis, and var. utahensis). More recent treatments such as Baldwin et al. (2012) and Welsh et al. (2015) simply recognize A. utahensis with four varieties distinguished: var. eborispina, var. kaibabensis, var. nevadensis, and var. utahensis.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2026-05-27
Change Date2026-05-27
Edition Date2026-05-27
Edition AuthorsKMW-NVHP (1997), rev. Soteropoulos (2026)
Threat ImpactHigh
Range Extent20,000-200,000 square km (about 8000-80,000 square miles)
Number of Occurrences81 - 300
Rank Reasons
Agave utahensis is a perennial succulent, forb to shrub found in calcareous or sandstone outcrops and limestone hillsides in desert scrub, pinyon-juniper woodland, or adjacent conifer woodlands. It is endemic to the southwestern United States in northern Arizona, eastern California, southern Nevada, and southwestern Utah within the Mojave Desert and Colorado Plateau. There are over 81, but likely fewer than 300, occurrences, which face numerous threats, with the highest impacts from mining, poaching (wild-foraged plants have been found in the nursery trade and for sale online), and increasing fire frequency and intensity. Trends are decreasing but not quantifiable. Monitoring of populations should be conducted to improve our understanding of reproduction, plant abundance, threats, and trends, as well as continuing conservation measures to protect the taxon.
Range Extent Comments
Agave utahensis is endemic to the southwestern United States in northern Arizona, eastern California, southern Nevada, and southwestern Utah within the Mojave Desert and Colorado Plateau (FNA 2002, Byers et al. 2014). Range extent was estimated to be over 74,000 square kilometers using herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1994 and 2025 (RARECAT 2025, GBIF 2026, iNaturalist 2026, NatureServe 2026, SEINet 2026).
Occurrences Comments
By applying a 1 km separation distance to herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1994 and 2025, it is estimated that there are over 81, but likely fewer than 300, occurrences rangewide (RARECAT 2025, GBIF 2026, iNaturalist 2026, NatureServe 2026, SEINet 2026).
Threat Impact Comments
This taxon faces threats from grazing, mining, transmission line and road construction and maintenance, poaching (wild-foraged plants have been found in the nursery trade and for sale online), recreational activities, increasing fire frequency and intensity, invasive annual grasses, browsing of inflorescences by animals, drought, and temperature extremes (NNHP 1995, Byers et al. 2014, Hodgson et al. 2020, UNHP 2024, CNDDB 2026, Ferguson, pers. comm., 2026, Lovera, pers. comm., 2026, NatureServe 2026).
Ecology & Habitat

Habitat

Agave utahensis grows in calcareous or sandstone outcrops and limestone hillsides in desert scrub, pinyon-juniper woodland, or adjacent conifer woodlands (FNA 2002, Hodgson et al. 2020).

Ecology

This taxon contributes to soil formation, creating areas of organic matter (Gentry 1982).

Reproduction

Most taxa within this group reproduce via seeds and rhizomes, which form pups, though Agave utahensis var. kaibabensis rarely produces rhizomes and relies on sexual reproduction (Hodgson et al. 2020).
Terrestrial Habitats
Woodland - ConiferWoodland - MixedShrubland/chaparralGrassland/herbaceousDesert
Other Nations (1)
United StatesN3
ProvinceRankNative
NevadaS3Yes
CaliforniaSNRYes
Navajo NationSNRYes
UtahSNRYes
ArizonaS3Yes
Threat Assessments
ThreatScopeSeverityTiming
2 - Agriculture & aquacultureRestricted - smallSlight or 1-10% pop. declineHigh (continuing)
2.3 - Livestock farming & ranchingRestricted - smallSlight or 1-10% pop. declineHigh (continuing)
3 - Energy production & miningRestricted - smallSerious or 31-70% pop. declineHigh (continuing)
3.2 - Mining & quarryingRestricted - smallSerious or 31-70% pop. declineHigh (continuing)
4 - Transportation & service corridorsRestricted - smallModerate or 11-30% pop. declineHigh (continuing)
4.1 - Roads & railroadsRestricted - smallModerate or 11-30% pop. declineHigh (continuing)
4.2 - Utility & service linesSmall (1-10%)Moderate or 11-30% pop. declineHigh (continuing)
5 - Biological resource useLarge (31-70%)Moderate or 11-30% pop. declineHigh (continuing)
5.2 - Gathering terrestrial plantsLarge (31-70%)Moderate or 11-30% pop. declineHigh (continuing)
5.2.1 - Intentional use (species being assessed is the target)Large (31-70%)Moderate or 11-30% pop. declineHigh (continuing)
6 - Human intrusions & disturbanceRestricted (11-30%)Moderate or 11-30% pop. declineHigh (continuing)
6.1 - Recreational activitiesRestricted (11-30%)Moderate or 11-30% pop. declineHigh (continuing)
7 - Natural system modificationsLarge (31-70%)Moderate or 11-30% pop. declineHigh (continuing)
7.1 - Fire & fire suppressionLarge (31-70%)Moderate or 11-30% pop. declineHigh (continuing)
7.1.1 - Increase in fire frequency/intensityLarge (31-70%)Moderate or 11-30% pop. declineHigh (continuing)
8 - Invasive & other problematic species, genes & diseasesUnknownUnknownHigh (continuing)
8.1 - Invasive non-native/alien species/diseasesUnknownUnknownHigh (continuing)
8.1.1 - Unspecified speciesUnknownUnknownHigh (continuing)
8.2 - Problematic native species/diseasesUnknownUnknownHigh (continuing)
8.2.1 - Unspecified speciesUnknownUnknownHigh (continuing)
11 - Climate change & severe weatherPervasive (71-100%)UnknownHigh (continuing)
11.2 - DroughtsPervasive (71-100%)UnknownHigh (continuing)
11.3 - Temperature extremesPervasive (71-100%)UnknownHigh (continuing)

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Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)Yes
Roadless Areas (14)
Arizona (2)
AreaForestAcres
Coconino RimKaibab National Forest7,213
Red PointKaibab National Forest7,139
Nevada (7)
AreaForestAcres
Angel Peak NorthHumboldt-Toiyabe National Forest12,577
Angel Peak SouthHumboldt-Toiyabe National Forest6,540
Charleston - Macks CynHumboldt-Toiyabe National Forest11,378
La Madre - ProspectHumboldt-Toiyabe National Forest278
Lovell Summit SouthHumboldt-Toiyabe National Forest28,455
PotosiHumboldt-Toiyabe National Forest5,145
Stirling - WheelerHumboldt-Toiyabe National Forest3,044
Utah (5)
AreaForestAcres
Bull ValleyDixie National Forest10,911
Cedar BenchDixie National Forest8,915
CottonwoodDixie National Forest6,754
Moody WashDixie National Forest31,835
Pine Valley MountainsDixie National Forest57,673
References (18)
  1. Baldwin, B. G., D. H. Goldman, D. J. Keil, R. Patterson, T. J. Rosatti, and D. H. Wilken, eds. 2012. The Jepson manual: vascular plants of California. 2nd edition. University of California Press, Berkeley, CA. 1568 pp.
  2. Byers, C., Maughan, P.J., Clouse, J., and J.R. Stewart. 2014. Microsatellite primers in <i>Agave utahensis</i> (Asparagaceae), a keystone species in the Mojave Desert and Colorado Plateau. Applications in Plant Sciences 2(9): 1400047.
  3. California Natural Diversity Database (CNDDB). 2026. RareFind Version 5.3.0. California Department of Fish and Game, Sacramento.
  4. Ferguson, Katie. Personal communication. Rare Plant Botanist. California Natural Diversity Database, Department of Fish and Wildlife, Sacramento.
  5. Flora of North America Editorial Committee (FNA). 2002a. Flora of North America north of Mexico. Vol. 26. Magnoliophyta: Liliidae: Liliales and Orchidales. Oxford Univ. Press, New York. xxvi + 723 pp.
  6. Gentry, H.S. 1982. Agaves of continental North America. Univ. Arizona Press, Tucson.
  7. Global Biodiversity Information Facility (GBIF). 2026. Global Biodiversity Information Facility (GBIF) data portal. Online. Available: https://www.gbif.org/ (accessed 2026).
  8. Hodgson, W., Salywon, A., and R. Puente. 2020. <i>Agave utahensis</i>. The IUCN Red List of Threatened Species 2020: e.T115698677A116354603. Online. Available: https://dx.doi.org/10.2305/IUCN.UK.2020-1.RLTS.T115698677A116354603.en (accessed 2026).
  9. iNaturalist. 2026. Online. Available: https://www.inaturalist.org (accessed 2026).
  10. 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.
  11. Lovera, J. Personal communication. Supervisory Botanist. Nevada Division of Natural Heritage. Carson City, NV.
  12. NatureServe. 2026. NatureServe Network Biodiversity Location Data. NatureServe, Arlington, Virginia.
  13. Navajo Natural Heritage Program (NNHP).1995. Element Subnational Ranking Form: <i>Agave utahensis</i> var. <i>kaibabensis</i> in Biotics 5 database. NatureServe, Arlington, Virginia (accessed 27 May 2026).
  14. <p>NatureServe's Rapid Analysis of Rarity and Endangerment Conservation Assessment Tool (RARECAT). 2025. Version: 2.1.1 (released April 04, 2025).</p>
  15. Slauson, L.A. 2001. Insights on the pollination biology of <i>Agave </i>(Agavaceae). Haseltonia 8: 10-23 .
  16. Southwest Environmental Information Network (SEINet). 2026. Collections Databases. Online. Available: https://swbiodiversity.org/seinet/collections/index.php (accessed 2026).
  17. Utah Natural Heritage Program (UNHP). 2024. Element Subnational Ranking Form: <i>Agave utahensis</i> var. <i>utahensis</i> in Biotics 5 database. NatureServe, Arlington, Virginia (accessed 27 May 2026).
  18. 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.