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CEGL005296 Canotia holacantha Grand Canyon Shrubland

The U.S. National
Vegetation Classification
Type Concept Sentence:
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Common (Translated Scientific) Name: Crucifixion-thorn Grand Canyon Shrubland
Colloquial Name:
Hierarchy Level: Association
Type Concept: This crucifixion-thorn shrubland association is currently described from Grand Canyon National Park in Arizona. More survey and classification work are needed to fully characterize this type. It occurs on sideslopes of canyons typically from 575 to 975 m (1875-3625 feet) elevation, but it has been found as high as 1275 m (4150 feet). It usually occurs on north-facing, moderately-sloping gradients (15-25°), but occasionally occurs on very steep slopes (40-50°) as well. Soils are rapidly-drained sandy loams; the underlying geology is usually limestone. This community often occurs in protected areas with a relatively high cover of moss. This community is characterized by a tall-shrub layer dominated by Canotia holacantha, which is invariably accompanied by the short shrub Ephedra fasciculata and occasionally by Acacia greggii. A variety of dwarf-shrubs also occur, including Gutierrezia microcephala, Echinocereus sp., Agave utahensis, and Encelia farinosa. A sparse graminoid layer is usually present, in which Bromus rubens occurs most frequently. The perennial grasses Muhlenbergia porteri and Tridens muticus also occur from time to time. Sphaeralcea grossulariifolia and Xylorhiza tortifolia are the most common forbs in a relatively sparse forb layer. Moss occurs sporadically, but when present has significant cover.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features:
Classification Comments: No Data Available
Similar NVC Types:
Physiognomy and Structure: No Data Available
Dynamics: No Data Available
Environmental Description: No Data Available
Geographic Range: This association is currently known from Grand Canyon National Park in Arizona. More survey work is needed to fully document its global range.
Nations: US
States/Provinces: AZ
US Forest Service Ecoregions (1994/1995)
Domain Name:
Division Name:
Province Name: Colorado Plateau Semi-Desert Province
Province Code: 313    Occurrence Status: Confident or certain
Section Name: Grand Canyon Lands Section
Section Code: 313A     Occurrence Status: Confident or certain
Omernik Ecoregions:
Confidence Level: Low
Confidence Level Comments:
Grank: GNR
Concept Lineage:
Obsolete Names:
Obsolete Parents:
Synonomy: = Canotia holacantha Grand Canyon Shrubland (Reid and Hall 2010)
Concept Author(s): M.S. Reid and M.E. Hall (2010)
Author of Description: R. Meszaros
Version Date: 30Jul2010
  • Kearsley, M. J. C., K. Green, M. Tukman, M. Reid, M. Hall, T. J. Ayers, and K. Christie. 2015. Grand Canyon National Park-Grand Canyon / Parashant National Monument vegetation classification and mapping project. Natural Resource Report NPS/GRCA/NRR--2015/913. National Park Service, Fort Collins, CO. 75 pp. plus appendices.
  • Reid, M. S., and M. E. Hall. 2010. Vegetation classification of Grand Canyon National Park. Draft report submitted to National Park Service, Fort Collins, CO.
  • Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.