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A4050 Ephedra viridis - Chrysothamnus viscidiflorus - Rhus trilobata Talus Sparse Scrub Alliance

Type Concept Sentence: This alliance consists of very open to sparse shrubs; typical species include Artemisia bigelovii, Atriplex canescens, Brickellia spp., Chrysothamnus viscidiflorus, Ephedra viridis, Ericameria nauseosa, Fallugia paradoxa, and/or Rhus trilobata. It occupies sparsely vegetated (<10% vascular plant cover) talus and colluvial slopes in the intermountain western U.S.

Common (Translated Scientific) Name: Mormon-tea - Yellow Rabbitbrush - Skunkbush Sumac Talus Sparse Scrub Alliance

Colloquial Name: Intermountain Talus Sparse Scrub

Hierarchy Level:  Alliance

Type Concept: This alliance consists of very open to sparse shrubs (<10% vascular plant cover); typical species include Artemisia bigelovii, Atriplex canescens, Brickellia spp., Chrysothamnus viscidiflorus, Ephedra viridis, Ericameria nauseosa, Fallugia paradoxa, and/or Rhus trilobata. It occupies sparsely vegetated talus and colluvial slopes. Sites range from dry and warm through some cooler aspects. Many types occur on tablelands and cliffs with talus and colluvial slopes below them. Substrates are predominantly sedimentary rocks, such as sandstone, shale, and limestone. These species are utilizing moisture from cracks and pockets where soil accumulates, and can tolerate rock-fall and movement since generally these are unstable substrates. These alliance occurs throughout the intermountain western U.S.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: Other associations in the west occur on talus and scree slopes from subalpine into the intermountain basins or low-elevation canyons. Most of these are currently placed into other groups. For now this alliance is constrained to generally sparsely vegetated talus, scree and colluvial slopes, but this treatment will need further review.

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: Sparsely vegetated with <10% vascular plant cover of evergreen and deciduous shrubs, generally <2 m in height.

Floristics: This alliance consists of very open to sparse shrubs (<10% vascular plant cover); typical species include Artemisia bigelovii, Atriplex canescens, Brickellia spp., Chrysothamnus viscidiflorus, Ephedra viridis, Ericameria nauseosa, Fallugia paradoxa, and/or Rhus trilobata.

Dynamics:  No Data Available
Environmental Description:  Sites occur predominantly on talus and colluvial slopes. Aspects are mostly dry and warm but range to cool. Many types occur on tablelands and cliffs with talus and colluvial slopes below them. Substrates are predominantly sedimentary rocks, such as sandstone, shale, and limestone. Plants are utilizing moisture from cracks and pockets where soil accumulates, and can tolerate rockfall and movement, since generally these are unstable substrates.
Geographic Range: This alliance occurs on the Colorado Plateau and extends west throughout the Great Basin and northeast into Wyoming.

Nations: US

States/Provinces:  AZ, CA, CO, ID, NM, NV, UT, WY


Confidence Level: Moderate

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.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.6 Saltbush species - Joint-fir species - Buckwheat species Intermountain Basins Sparse Vegetation Macrogroup M118 3.B.1.Ne.6
Group 3.B.1.Ne.6.a Saltbush species - Mountain-mahogany species - Joint-fir species Intermountain Basins Sparse Vegetation Group G570 3.B.1.Ne.6.a
Alliance A4050 Mormon-tea - Yellow Rabbitbrush - Skunkbush Sumac Talus Sparse Scrub Alliance A4050 3.B.1.Ne.6.a
Association CEGL001287 Fourwing Saltbush - Mormon-tea Talus Shrubland CEGL001287 3.B.1.Ne.6.a
Association CEGL002347 Yellow Rabbitbrush Talus Shrubland CEGL002347 3.B.1.Ne.6.a
Association CEGL002927 Fourwing Saltbush - (Mormon-tea) / (Bush Muhly) Sandstone Sparse Vegetation CEGL002927 3.B.1.Ne.6.a
Association CEGL003496 Apache Plume - Brickellbush species - (Rockspirea) Scree Shrubland CEGL003496 3.B.1.Ne.6.a
Association CEGL003755 Bigelow''s Sagebrush - (Mormon-tea, Torrey''s Joint-fir) Talus Shrubland CEGL003755 3.B.1.Ne.6.a
Association CEGL003776 Skunkbush Sumac - (Mormon-tea, Torrey''s Joint-fir) Talus & Slickrock Shrubland CEGL003776 3.B.1.Ne.6.a
Association CEGL003961 Rubber Rabbitbrush – (Mojave Woody-aster) Talus Sparse Shrubland CEGL003961 3.B.1.Ne.6.a
Concept Lineage: No Data Available

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: No Data Available
Concept Author(s): M.S. Reid, in Faber-Langendoen et al. (2013)

Author of Description: M.S. Reid

Acknowledgements: No Data Available

Version Date: 12-18-14
  • 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.
  • Hansen, M., J. Coles, K. A. Thomas, D. Cogan, M. Reid, J. Von Loh, and K. Schulz. 2004b. USGS-NPS Vegetation Mapping Program: Wupatki National Monument, Arizona, vegetation classification and distribution. U.S. Geological Survey Technical Report. Southwest Biological Science Center, Flagstaff, AZ. 229 pp.