Home/Species/ Palmer Oak

Quercus palmeri

Engelm.

Palmer Oak

G4Apparently Secure Found in 9 roadless areas NatureServe Explorer →

G4Apparently SecureGlobal Rank

Near threatenedIUCN

MediumThreat Impact

Identity

Unique IDELEMENT_GLOBAL.2.131143

Element CodePDFAG050E0

Record TypeSPECIES

ClassificationSpecies

Classification StatusStandard

Name CategoryVascular Plant

IUCNNear threatened

Endemicoccurs (regularly, as a native taxon) in multiple nations

KingdomPlantae

PhylumAnthophyta

ClassDicotyledoneae

OrderFagales

FamilyFagaceae

GenusQuercus

Synonyms

Quercus dunniiKellogg

Other Common Names

Dunn's Oak (EN) Palmer oak (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

Quercus palmeri is the earliest available name for this taxon, Kartesz (1999) used the name Quercus dunnii, an illegitimate and superfluous name, for this entity (IPNI 2025).

Conservation Status

Rank MethodLegacy Rank calculation - Biotics v1

Review Date2020-04-28

Change Date2020-04-28

Edition Date2020-04-28

Edition AuthorsTreher (2020)

Threat ImpactMedium

Range Extent200,000-2,500,000 square km (about 80,000-1,000,000 square miles)

Number of Occurrences81 to >300

Rank Reasons

Quercus palmeri occurs in Arizona, New Mexico, California, and northern Baja California (Mexico). Records from Arizona and New Mexico possibly represent hybrid material. The species has many occurrences in California and Baja California but they are generally isolated across a fragmented range, which is attributed to a decline after the Pleistocene when climatic conditions changed. Current trends are not known. There are a large number of occurrences on public lands but those on private land are likely threatened by development. Overall, threats are also not well understood.

Range Extent Comments

Quercus palmeri occurs in Arizona, New Mexico, California, and northern Baja California (Mexico). Records from Arizona and New Mexico possibly represent hybrid material with Quercus chrysolepis (FNA 1997).

Occurrences Comments

The number of occurrences is unknown. The species has numerous isolated populations that are relicts of a larger range that likely retracted due to more arid conditions after the Pleistocene. Some occurrences are shown to represent a single clone. A clone in the Jurupa Mountains of Riverside County, California is thought to be over 13,000 years old (May et al. 2009).

Threat Impact Comments

The range of Quercus palmeri has been contracting since the Pleistocene, with occurrences becoming more fragmented and isolated. Climate change is likely to continue this trend to some degree (Ramírez-Preciado et al. 2019). A large number of occurrences are on public lands where some protection is afforded. Outside of those public lands, development is certainly a threat.

Ecology & Habitat

Habitat

This species occurs on rocky slopes of canyons, flats, and mountain washes in shrublands (FNA 1997, Jepson Flora Project 2020).

Terrestrial Habitats

Shrubland/chaparral

Other Nations (1)

United StatesN4

Province	Rank	Native
New Mexico	SNR	Yes
Arizona	SNR	Yes
California	SNR	Yes

Threat Assessments

Threat	Scope	Severity	Timing
1 - Residential & commercial development	Unknown	Unknown	High (continuing)
11 - Climate change & severe weather	Pervasive (71-100%)	Slight or 1-10% pop. decline	High - low

Plant Characteristics

DurationPERENNIAL, EVERGREEN

Economic Value (Genus)No

Roadless Areas (9)

Arizona (5)

Area	Forest	Acres
Arnold Mesa	Prescott National Forest	12,286
Blind Indian Creek	Prescott National Forest	26,847
Hackberry	Coconino National Forest	17,885
Mazatzal	Tonto National Forest	16,942
Muldoon	Prescott National Forest	5,821

California (4)

Area	Forest	Acres
Cactus Springs B	San Bernardino National Forest	3,106
Deep Creek	San Bernardino National Forest	23,869
Pleasant View	Angeles National Forest	26,395
Pyramid Peak B	San Bernardino National Forest	7,194

References (8)

Flora of North America Editorial Committee (FNA). 1997. Flora of North America north of Mexico. Vol. 3. Magnoliophyta: Magnoliidae and Hamamelidae. Oxford Univ. Press, New York. xxiii + 590 pp.
International Plant Names Index (IPNI). 2025. Online. Available: http://www.ipni.org. (Accessed 2025).
Jepson Flora Project (eds.) 2020. Jepson eFlora. Online. Available: http://ucjeps.berkeley.edu/IJM.html (accessed 2020).
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.
Kartesz, J.T. 1999. A synonymized checklist and atlas with biological attributes for the vascular flora of the United States, Canada, and Greenland. First edition. In: Kartesz, J.T., and C.A. Meacham. Synthesis of the North American Flora, Version 1.0. North Carolina Botanical Garden, Chapel Hill, N.C.
Little, E.L., Jr. 1979. Checklist of United States trees (native and naturalized). Agriculture Handbook No. 541. U.S. Forest Service, Washington, D.C. 375 pp.
May, M.R., M.C. Provance, A.C. Sanders, N.C. Ellstrand, and J. Ross-Ibarra. 2009. A Pleistocene Clone of Palmer's Oak Persisting in Southern California. PLoS ONE 4(12).
Ramírez-Preciado, R.P. , J. Gasca-Pineda, and M.C.Arteaga. 2019. Effects of global warming on the potential distribution ranges of six <i>Quercus</i> species (Fagaceae). Flora 251:32-38.

Quercus palmeri

Habitat

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