Print Report

A0833 Purshia stansburiana Scrub Alliance

Type Concept Sentence: This alliance consists of shrublands dominated by Purshia stansburiana. It occurs throughout the Intermountain West at middle elevations (800-2000 m) on edges of intermittent watercourses, canyons, hills, steep slopes, and cliffs. Soils are well-drained, shallow, rocky, rapidly permeable, and usually calcareous.

Common (Translated Scientific) Name: Stansbury''s Cliffrose Scrub Alliance

Colloquial Name: Stansbury''s Cliffrose Scrub

Hierarchy Level:  Alliance

Type Concept: This alliance consists of shrublands dominated by Purshia stansburiana. Associated shrubs include Agave utahensis, Artemisia nova, Artemisia tridentata, Coleogyne ramosissima, Ephedra viridis, Ericameria nauseosa, Mortonia utahensis, and Yucca baccata. The herbaceous ground layer is typically sparse and includes Achnatherum speciosum, Poa secunda, Pseudoroegneria spicata, and Sporobolus cryptandrus. Emergent Juniperus osteosperma and Pinus monophylla trees may be present. Stands occur throughout the Intermountain West at middle elevations (800-2000 m) on edges of intermittent watercourses, canyons, hills, steep slopes, and cliffs. Soils are well-drained, shallow, rocky, rapidly permeable, and usually calcareous, but it is known to occur on limestone. Precipitation averages 20-45 cm annually. The alliance in California is restricted to mountains of the eastern Mojave Desert and adjacent Great Basin. It occurs in small, scattered stands on relatively steep slopes, which are often adjacent to Pinus monophylla stands or Artemisia tridentata or Purshia tridentata shrublands. Virtually all stands observed occur on limestone or marble. Disturbance from flooding is likely in the canyon bottom stands.

Diagnostic Characteristics: Shrublands dominated by or with a significant component of Purshia stansburiana.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: All the associations in the alliance for the western U.S. are based upon the old taxon of Purshia mexicana var. stansburiana, which is now treated as Purshia stansburiana. Purshia mexicana is considered by most taxonomists to occur in far southern Arizona and into Mexico, with Purshia stansburiana occurring in the Colorado Plateau, Great Basin and Mojave regions.

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: These are microphyllous evergreen shrublands that grows up to 8 m tall.

Floristics: This alliance consists of shrublands dominated by Purshia stansburiana. Associated shrubs include Agave utahensis, Artemisia nova, Artemisia tridentata, Coleogyne ramosissima, Ephedra viridis, Ericameria nauseosa (= Chrysothamnus nauseosus), Mortonia utahensis, and Yucca baccata. The herbaceous ground layer is typically sparse and includes Achnatherum speciosum, Poa secunda, Pseudoroegneria spicata, and Sporobolus cryptandrus. Emergent Juniperus osteosperma and Pinus monophylla trees may be present.

Dynamics:  Fire is probably infrequent in this alliance since stands are relatively open and have low fuel loads. The ability of Purshia stansburiana to sprout after fire varies geographically. In general, it appears to be a weak sprouter, and plants are usually killed after severe and even light fires (Howard 1995). Purshia stansburiana does not appear to sprout after fire in California, and fire in the rocky, sparsely vegetated stands is probably very rare. Price and Brotherson (1987) report that there has been a noticeable decline in recruitment of Purshia stansburiana since 1957 at sites in Utah. They attributed the decline to competitive exclusion and increased fire frequency associated with invasion by non-native annual grasses.
Environmental Description:  The vegetation in this alliance occurs at middle elevations (800-2000 m) of the Intermountain West, usually in washes, on cliffs, or on steep, rocky terrain. Precipitation averages 20-45 cm annually. These communities occur on skeletal soils derived from granitic or sedimentary parent materials. In central Utah the alliance is associated with limestone (Price and Brotherson 1987).
Geographic Range: This alliance has been described from Arizona, California and Utah but may occur elsewhere across the southwest from southeastern California east to Colorado and south into Mexico.

Nations: MX?,US

States/Provinces:  AZ, CA, CO?, NV?, UT


Confidence Level: Moderate

Confidence Level Comments: No Data Available
Grank: G3

Greasons: No Data Available
Type Name Database Code Classification Code
Class 3 Desert & Semi-Desert Class C03 3
Subclass 3.B Cool Semi-Desert Scrub & Grassland Subclass S11 3.B
Formation 3.B.1 Cool Semi-Desert Scrub & Grassland Formation F033 3.B.1
Division 3.B.1.Ne Western North American Cool Semi-Desert Scrub & Grassland Division D040 3.B.1.Ne
Macrogroup 3.B.1.Ne.1 Yellow Rabbitbrush - Blackbrush / Indian Ricegrass Dry Shrubland & Grassland Macrogroup M171 3.B.1.Ne.1
Group 3.B.1.Ne.1.a Joshua Tree - Eastern Mojave Buckwheat - Rough Joint-fir Mixed Desert Scrub Group G296 3.B.1.Ne.1.a
Alliance A0833 Stansbury''s Cliffrose Scrub Alliance A0833 3.B.1.Ne.1.a
Association CEGL001053 Stansbury''s Cliffrose / Bluebunch Wheatgrass Shrubland CEGL001053 3.B.1.Ne.1.a
Association CEGL002948 Stansbury''s Cliffrose - Greenleaf Manzanita Shrubland CEGL002948 3.B.1.Ne.1.a
Association CEGL002957 Stansbury''s Cliffrose Shrubland CEGL002957 3.B.1.Ne.1.a
Association CEGL004011 Stansbury''s Cliffrose - Crispleaf Wild Buckwheat Shrubland CEGL004011 3.B.1.Ne.1.a
Concept Lineage: equivalent to A.833

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: ? Cowania mexicana var. stansburiana (Price and Brotherson 1987)
= Purshia stansburiana (Stansbury cliff rose scrub) Alliance (Sawyer et al. 2009) [33.240.00]
= Purshia stansburiana Shrubland Alliance (Evens et al. 2014)
= Purshia stansburiana Shrubland Alliance (CNPS 2017) [33.240.00]
>< Big Sagebrush Scrub (#35210) (Holland 1986b)
>< Great Basin Mixed Scrub (#35100) (Holland 1986b)
>< Sagebrush Steppe (#35300) (Holland 1986b)
< Singleleaf pinyon-Utah juniper series (Sawyer and Keeler-Wolf 1995)
Concept Author(s): D. Sarr, in Faber-Langendoen et al. (2013)

Author of Description: M.S. Reid

Acknowledgements: No Data Available

Version Date: 12-18-14
  • CNPS [California Native Plant Society]. 2015-2017. A manual of California vegetation [online]. California Native Plant Society, Sacramento, CA. [http://vegetation.cnps.org/].
  • Evens, J. M., K. Sikes, D. Hastings, and J. Ratchford. 2014. Vegetation alliance descriptions for Lake Mead National Recreation Area, Death Valley National Park and Mojave National Preserve. Unpublished report submitted to USDI National Park Service, Mojave Desert Network Inventory and Monitoring Program. California Native Plant Society, Sacramento, CA.
  • Faber-Langendoen, D., J. Drake, M. Hall, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, M. Russo, K. Schulz, L. Sneddon, K. Snow, and J. Teague. 2013-2019b. Screening alliances for induction into the U.S. National Vegetation Classification: Part 1 - Alliance concept review. NatureServe, Arlington, VA.
  • Holland, R. F. 1986b. Preliminary descriptions of the terrestrial natural communities of California. Unpublished report prepared for the California Department of Fish and Game, Nongame-Heritage Program and Natural Diversity Database, Sacramento. 156 pp.
  • Howard, J. L. 1995. Purshia mexicana var. stansburiana. In: Fire Effects Information System [Online]. USDA Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). [http://www.fs.fed.us/database/feis/] (accessed 28 June 2011).
  • Keeler-Wolf, T., and K. Thomas. 2000. Draft descriptions of vegetation alliances for the Mojave Ecosystem Mapping project. California Natural Diversity Database, California Department of Fish and Game, Sacramento.
  • Mozingo, H. 1987. Shrubs of the Great Basin: A natural history. University of Nevada Press, Las Vegas. 342 pp.
  • Price, K. P., and J. D. Brotherson. 1987. Habitat and community relationships of cliffrose (Cowania mexicana var. stansburiana) in central Utah. Great Basin Naturalist 47(1):132-151.
  • Reid, M. S., K. A. Schulz, P. J. Comer, M. H. Schindel, D. R. Culver, D. A. Sarr, and M. C. Damm. 1999. An alliance level classification of vegetation of the coterminous western United States. Unpublished final report to the University of Idaho Cooperative Fish and Wildlife Research Unit and National Gap Analysis Program, in fulfillment of Cooperative Agreement 1434-HQ-97-AG-01779. The Nature Conservancy, Western Conservation Science Department, Boulder, CO.
  • Sawyer, J. O., T. Keeler-Wolf, and J. Evens. 2009. A manual of California vegetation. Second edition. California Native Plant Society, Sacramento CA. 1300 pp.
  • Sawyer, J. O., and T. Keeler-Wolf. 1995. A manual of California vegetation. California Native Plant Society, Sacramento. 471 pp.
  • Warren, P. L., K. L. Reichhardt, D. A. Mouat, B. T. Brown, and R. R. Johnson. 1982. Vegetation of Grand Canyon National Park. Cooperative National Park Resources Studies Unit Technical Report 9. Tucson, AZ. 140 pp.