Print Report

A4187 Acacia greggii - Hyptis emoryi - Justicia californica Desert Wash Scrub Alliance

Type Concept Sentence: Acacia greggii, Hyptis emoryi, or Justicia californica is dominant or codominant in the shrub canopy with other desert shrubs. This alliance is found in the Colorado and Sonoran deserts of Arizona, California, Nevada, and possibly Baja California, Mexico, in arroyos, channels, rocky alluvial washes, bajadas, canyon walls, seeps, and springs and steep, very rocky colluvium on lower canyon slopes, and valleys.

Common (Translated Scientific) Name: Catclaw Acacia - Desert-lavender - Beloperone Desert Wash Scrub Alliance

Colloquial Name: Catclaw Acacia - Desert-lavender - Beloperone Desert Wash Scrub

Hierarchy Level:  Alliance

Type Concept: Acacia greggii, Hyptis emoryi, or Justicia californica is dominant or codominant in the shrub canopy with Adenophyllum porophylloides, Ambrosia eriocentra, Bebbia juncea, Encelia farinosa, Encelia virginensis, Ephedra californica, Ephedra nevadensis, Ericameria teretifolia, Eriogonum fasciculatum, Hymenoclea salsola, Larrea tridentata, Cylindropuntia acanthocarpa, Opuntia basilaris, Prunus fasciculata, Psorothamnus schottii, Rhus ovata, Salazaria mexicana, Salvia dorrii, Senna armata, Trixis californica, Viguiera parishii, and Yucca schidigera. Emergent trees may be present at low cover, including Chilopsis linearis, Fouquieria splendens, Juniperus californica, Juniperus osteosperma, Olneya tesota, Parkinsonia florida, and/or Psorothamnus spinosus. This alliance is found in the Colorado and Sonoran deserts of Arizona, California, Nevada, and possibly Baja California, Mexico. It occurs in arroyos, channels, rocky alluvial washes, bajadas, canyon walls, seeps, and springs and steep, very rocky colluvium on lower canyon slopes, and valleys. Soils are coarse, well-drained, and moderately acidic to slightly saline or gravelly sands and loams surrounding boulders and bedrock.

Diagnostic Characteristics: Acacia greggii, Hyptis emoryi, or Justicia californica >2% absolute cover and >50% relative cover in the tall-shrub or low tree canopy (Keeler-Wolf et al. 1998a). No other single, tall-shrub species with greater cover, but Prunus fasciculata may be equal to or slightly greater in cover. Smaller shrubs, such as Ericameria paniculata or Hymenoclea salsola, may have cover up to twice the cover of nominals (Thomas et al. 2004, Keeler-Wolf et al. 2005).

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: This alliance combines 3 alliances from Sawyer et al. (2009): Acacia greggii Shrubland Alliance, Hyptis emoryi Shrubland Alliance, and Justicia californica Provisional Shrubland Alliance.

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: Shrubs <3 m; canopy is open to intermittent. Herbaceous layer is sparse to intermittent with seasonal annuals.

Floristics: Acacia greggii, Hyptis emoryi, or Justicia californica is dominant or codominant in the open to intermittent shrub canopy <3 m tall, with Adenophyllum porophylloides, Ambrosia eriocentra, Bebbia juncea, Encelia farinosa, Encelia virginensis, Ephedra californica, Ephedra nevadensis, Ericameria teretifolia, Eriogonum fasciculatum, Hymenoclea salsola (= Ambrosia salsola), Larrea tridentata, Cylindropuntia acanthocarpa, Opuntia basilaris, Prunus fasciculata, Psorothamnus schottii, Rhus ovata, Salazaria mexicana, Salvia dorrii, Senna armata, Trixis californica, Viguiera parishii, and Yucca schidigera. Emergent trees may be present at low cover, including Chilopsis linearis, Fouquieria splendens, Juniperus californica, Juniperus osteosperma, Olneya tesota, Parkinsonia florida, and/or Psorothamnus spinosus.

Dynamics:  The alliance occupies habitats similar to those of other leguminous microphyll alliances of the desert Southwest but extends farther north into the Mojave Desert than other frost-sensitive trees. It is characteristic of hot, low elevations, where stands occupy washes, valley bottoms, and slopes on which outcrops and boulders channel the surface water to roots. Stands are typically uneven-aged (Uchytil 1990c).

Little information exists on variation in flood frequencies (Waananen and Crippen 1977). It is likely that only the largest 100-year floods act as stand-replacing events, while lower flood intervals and intensities establish seedlings in favorable microsites. Flooding intensities in stands along washes are highly variable; however, relatively low discharges are sufficient in small concentrated channels to initiate seed dispersal and germination (Uchytil 1990c).

Fluvial processes rather than fire primarily disturb the alliance, but Acacia greggii has a strong ability to sprout after disturbance. Invasions of non-native annual grasses such as Bromus rubens create fine fuels that can carry surface fires. Repeated burning could increase the importance of Acacia greggii over time, and Acacia greggii stands may replace other upland types with prolonged browsing or fire.
Environmental Description:  Small stands occur along many of the narrow washes throughout the Colorado and Sonoran deserts, and in the southern portion of the Mojave Desert below 800 m. They occur as narrow strips that ascend drainages in old dissected alluvial fans or badlands or are associated with rocky and boulder-strewn stretches. They tend to occur along drainages that are not big enough to support stands of the larger microphyllous legumes, though these trees may be emergents in this alliance. It also occurs in arroyos, channels, rocky alluvial washes, bajadas, canyon walls, seeps, and springs and steep, very rocky colluvium on lower canyon slopes, and valleys. Soils are coarse, well-drained, and moderately acidic to slightly saline or gravelly sands and loams surrounding boulders and bedrock.
Geographic Range: This alliance is found in the Colorado and Sonoran deserts of Arizona, California, Nevada, and possibly Baja California, Mexico.

Nations: MX?,US

States/Provinces:  AZ, CA, MXBCN?, NV


Confidence Level: Low

Confidence Level Comments: No Data Available
Grank: GNR

Greasons: No Data Available
Type Name Database Code Classification Code
Class 3 Desert & Semi-Desert Class C03 3
Subclass 3.A Warm Desert & Semi-Desert Woodland, Scrub & Grassland Subclass S06 3.A
Formation 3.A.2 Warm Desert & Semi-Desert Scrub & Grassland Formation F015 3.A.2
Division 3.A.2.Na North American Warm Desert Scrub & Grassland Division D039 3.A.2.Na
Macrogroup 3.A.2.Na.7 North American Warm-Desert Xeric-Riparian Scrub Macrogroup M092 3.A.2.Na.7
Group 3.A.2.Na.7.a Desert-willow - Apache Plume - Desert Almond Desert Wash & Colluvial Slope Group G541 3.A.2.Na.7.a
Alliance A4187 Catclaw Acacia - Desert-lavender - Beloperone Desert Wash Scrub Alliance A4187 3.A.2.Na.7.a
Association CEGL002960 Desert-lavender Shrubland CEGL002960 3.A.2.Na.7.a
Association CEGL005053 Catclaw Acacia Shrubland CEGL005053 3.A.2.Na.7.a
Association CEGL005390 Catclaw Acacia Wash Shrubland CEGL005390 3.A.2.Na.7.a
Association CEGL005737 Catclaw Acacia - (Woolly-fruit Bur-ragweed, Purple Sage) Desert Wash Shrubland CEGL005737 3.A.2.Na.7.a
Association CEGL005738 Catclaw Acacia - Desert Almond Desert Wash Shrubland CEGL005738 3.A.2.Na.7.a
Association CEGL009522 Catclaw Acacia - Creosotebush - Burrobrush Desert Wash Shrubland CEGL009522 3.A.2.Na.7.a
Concept Lineage: No Data Available

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: > Acacia greggii (Catclaw acacia thorn scrub) Alliance (Sawyer et al. 2009) [33.040.00]
> Acacia greggii Shrubland Alliance (Evens et al. 2014)
> Acacia greggii Shrubland Alliance (Keeler-Wolf et al. 2005)
> Acacia greggii Shrubland Alliance (Evens et al. 2012)
> Acacia greggii Shrubland Alliance (CNPS 2017) [33.040.00]
> Hyptis emoryi (Desert lavender scrub) Alliance (Sawyer et al. 2009) [33.190.00]
> Hyptis emoryi Shrubland Alliance (Evens et al. 2014)
> Hyptis emoryi Shrubland Alliance (Keeler-Wolf et al. 2005)
> Hyptis emoryi Shrubland Alliance (CNPS 2017) [33.190.00]
> Justicia californica (Chuparosa patches) Provisional Alliance (Sawyer et al. 2009) [33.340.00]
> Justicia californica Provisional Shrubland Alliance (Keeler-Wolf et al. 2005)
> Justicia californica Provisional Shrubland Alliance (CNPS 2017) [33.340.00]
>< Desert Dry Wash Woodland (#62200) (Holland 1986b)
? Mojave Wash Scrub (#34250) (Holland 1986b)
? Wash Woodland (Barbour and Major 1977)
Concept Author(s): M.S. Reid and J. Evens, after Sawyer et al. (2009)

Author of Description: M.J. Russo after Sawyer et al. (2009)

Acknowledgements: No Data Available

Version Date: 03-14-14
  • Armstrong, J. D. 1969. Vegetation of the Virgin Mountains, Clark County, Nevada. Unpublished thesis, University of Nevada, Las Vegas. 104 pp.
  • Barbour, M. G., and J. Major, editors. 1977. Terrestrial vegetation of California. John Wiley and Sons, New York. 1002 pp.
  • Brown, D. E., C. H. Lowe, and J. F. Hausler. 1977a. Southwestern riparian communities: Their biotic importance and management in Arizona. Pages 201-211 in: Importance, preservation and management of the riparian habitat. July 9, 1977, Tucson, AZ.
  • Brown, D. E., editor. 1982a. Biotic communities of the American Southwest-United States and Mexico. Desert Plants Special Issue 4(1-4):1-342.
  • 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. 2000. Water course vegetation on granite and calcareous substrates in the eastern Mojave Desert, California. Master''s thesis, Humboldt State University, Arcata, CA.
  • Evens, J. M., D. Roach-McIntosh, and D. Stout. 2012. Vegetation descriptions for Joshua Tree National Park. Unpublished report submitted to USDI, National Park Service, Mojave Desert Inventory and Monitoring Network. California Native Plant Society, Sacramento, CA.
  • 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.
  • Evens, J. M., and S. Hartman. 2007. Vegetation survey and classification for the Northern and Eastern Colorado Desert Coordinated Management Plan (NECO). CNPS Vegetation Program, Sacramento, CA.
  • Evens, J., and S. San. 2006. Vegetation alliances of the San Dieguito River Park region, San Diego County, California. Final report (August 2005) Version 2 (revised May 2006). Prepared by California Native Plant Society in cooperation with the California Natural Heritage Program of the California Department of Fish and Game and San Diego Chapter of the California Native Plant Society. Sacramento, CA. 271 pp.
  • 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.
  • Johnson, H. B. 1976. Vegetation and plant communities of southern California deserts. Pages 125-162 in: J. Latting, editor. Plant communities of southern California. Symposium proceedings. Special Publication No. 2. California Native Plant Society, Sacramento, CA.
  • Kearney, T. H., and R. H. Peebles, and collaborators. 1969. Arizona flora. University of California, Berkeley, CA. 1085 pp.
  • Keeler-Wolf, T. 2007. Mojave Desert scrub vegetation. Pages 609-656 in: M. G. Barbour, T. Keeler-Wolf, and A. A. Schoenherr, editors. Terrestrial vegetation of California. Third edition. University of California Press, Berkeley.
  • Keeler-Wolf, T., C. Roye, and K. Lewis. 1998a. Vegetation mapping and classification of the Anza-Borrego Desert State Park, California. Unpublished report on file at California Natural Diversity Database, California Department Fish and Game, Sacramento.
  • Keeler-Wolf, T., S. San, and D. Hickson. 2005. Vegetation classification of Joshua Tree National Park, Riverside and San Bernardino counties, California. Unpublished report to the National Park Service. California Fish and Game and California Native Plant Society, Sacramento, CA.
  • 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.
  • Klein, A., and J. Evens. 2006. Vegetation alliances of western Riverside County, California. Contract Number: P0185404. Final report prepared for The California Department of Fish and Game, Habitat Conservation Division. California Native Plant Society, Sacramento, CA. 332 pp. [http://www.dfg.ca.gov/biogeodata/vegcamp/pdfs/VegMappingRpt_Western_Riverside.pdf]
  • MacMahon, J. A. 1988. Warm deserts. Pages 232-264 in: M. G. Barbour and W. D. Billings, editors. North American terrestrial vegetation. Cambridge University Press, New York.
  • Paysen, T. E., J. A. Derby, H. Black, Jr., V. C. Bleich, and J. W. Mincks. 1980. A vegetation classification system applied to southern California. General Technical Report PSW-45. USDA Forest Service, USDA Forest Service, Pacific Southwest Research Station, Berkeley, CA.
  • 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.
  • Smith, S. D., and C. L. Douglas. 1989. The ecology of saltcedar (Tamarix chinensis) in Death Valley National Monument and Lake Mead National Recreation Area: An assessment of techniques and monitoring for saltcedar control in the park system. University of Nevada Cooperative National Park Resources Studies Unit Report 041/03, Las Vegas. 63 pp.
  • Spolsky, A. M. 1979. An overview of the plant communities of Anza Borrego Desert State Park. Unpublished report. State of California, The Resource Agency, Department of Parks and Recreation , Anza-Borrego Desert State Park, Borrego Springs, CA.
  • Thomas, K. A., T. Keeler-Wolf, J. Franklin, and P. Stine. 2004. Mojave Desert Ecosystem Program: Central Mojave vegetation mapping database. U.S. Geological Survey, Western Regional Science Center. 251 pp.
  • Thorne, R. F. 1976. The vascular plant communities of California. Pages 1-31 in: J. Latting, editor. Plant communities of southern California. California Native Plant Society, Sacramento.
  • Thorne, R. F. 1982. The desert and other transmontane plant communities of southern California. Aliso 10(2):219-257.
  • Turner, R. M., and D. E. Brown. 1982. Sonoran Desert scrub. Desert Plants 4:181-221.
  • Uchytil, R. J. 1990c. Acacia greggii. In: Fire Effects Information System [Online]. USDA Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). [http://www.fs.fed.us/database/feis/]
  • Vasek, F. C., and M. G. Barbour. 1988. Mojave Desert scrub vegetation. Pages 835-867 in: M. G. Barbour and J. Major, editors. Terrestrial vegetation of California: New expanded edition. Special Publication 9, California Native Plant Society, Sacramento. 1030 pp.
  • VegCAMP and AIS [Vegetation Classification and Mapping Program and Aerial Information Systems, Inc.]. 2013. 2012 California desert vegetation map and accuracy assessment in support of the Desert Renewable Energy Conservation Plan. Unpublished report to California Department of Fish and Wildlife Renewable Energy Program and the California Energy Commission. California Department of Fish and Wildlife, Vegetation Classification and Mapping Program and Aerial Information Systems, Inc.
  • Waananen, G. R., and H. Crippen. 1977. Streamflow records from California stream gages. Bulletin 102, California Department of Water Resources, Sacramento, CA.
  • Warren, P. L., B. K. Mortensen, B. D. Treadwell, J. E. Bowers, and K. L. Reichhardt. 1981. Vegetation of Organ Pipe Cactus National Monument. Cooperative National Park Resources Studies Unit Technical Report 7. Tucson, AZ. 140 pp.