Print Report

G677 Eragrostis lehmanniana - Bromus rubens - Brassica tournefortii Warm Desert Ruderal Grassland Group

Type Concept Sentence: This broadly defined ruderal group occurs in Arizona and northern Mexico and includes all exotic-dominated herbaceous stands without a shrub layer. Characteristic understory species include Brassica nigra, Brassica tournefortii, Bromus madritensis, Bromus rubens, Eragrostis lehmanniana, Erodium cicutarium, and Schismus barbatus.

Common (Translated Scientific) Name: Lehmann''s Lovegrass - Red Brome - Asian Mustard Warm Desert Ruderal Grassland Group

Colloquial Name: North American Warm Desert Ruderal Grassland

Hierarchy Level:  Group

Type Concept: This broadly defined ruderal group occurs in Arizona and northern Mexico and elsewhere in the Desert Southwest. It includes all desert scrub with an exotic species-dominated understory (>90% relative cover) in the herbaceous layer as well as exotic-dominated herbaceous stands. These open to dense grasslands and forblands are composed of either exotic annual or biennial grasses or forbs with low cover of perennial species (<10% absolute cover) or stands with a significant perennial herbaceous layer (>10% absolute cover) strongly dominated by exotics (>90% relative cover) with or without annuals and biennials present to dominant. Characteristic understory species include Brassica nigra, Brassica tournefortii, Bromus madritensis, Bromus rubens, Cynodon dactylon, Eragrostis lehmanniana, Erodium cicutarium, Schismus arabicus, Schismus barbatus, and Sorghum halepense with little native composition remaining. Other woody species may include Calliandra eriophylla, Gutierrezia sarothrae, or Isocoma tenuisecta. Gutierrezia microcephala is abundant in some stands. Remnant native desert grasses may be present with low cover. Other common herbaceous species include Allionia incarnata, Ambrosia confertiflora, Boerhavia erecta, Mollugo verticillata, Cylindropuntia versicolor, Panicum hirticaule, Polygala barbeyana, Proboscidea parviflora, and Phemeranthus aurantiacus. The native annual forb Amaranthus palmeri often codominates. This desert grassland and shrubland group occurs in southeastern Arizona on alluvial fans, ridges, hills and valley floors. The elevation range is 960-1100 m (3150-3600 feet). Climate is warm, semi-arid to arid continental. Mean annual precipitation ranges from 22-28 cm, but can vary greatly from year to year. Drought is not uncommon. Sites occur on gentle to moderate slopes. Substrates are variable but are often well-drained sandy loam.

Diagnostic Characteristics: This broadly defined upland ruderal group occurs in a warm, semi-arid climate in Arizona and northern Mexico and includes open to dense grasslands and forblands that are composed of either exotic annual or biennial grasses or forbs with low cover of perennial species (<10% absolute cover) or stands with a significant perennial herbaceous layer (>10% absolute cover) strongly dominated by exotics (>90% relative cover) with or without annuals and biennials present to dominant. Characteristic understory species include Brassica nigra, Brassica tournefortii, Bromus madritensis, Bromus rubens, Cynodon dactylon, Eragrostis lehmanniana, Erodium cicutarium, Schismus arabicus, Schismus barbatus, and Sorghum halepense with little native composition remaining. The ruderal native annual forb Amaranthus palmeri often dominates or codominates disturbed stands.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: Some of the characteristic species are shared with other ruderal types; however, this type is restricted to warm deserts and the transition zone with the southern Great Basin. Sorghum halepense and Cynodon dactylon grow best in mesic conditions. Stands dominated by these species that occur in riparian areas are not included in this group.

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: The physiognomy of this group includes grasslands and forblands with a sparse to dense, annual- or perennial-dominated herbaceous layer.

Floristics: This broadly defined ruderal group includes open to dense grasslands and forblands that are composed of either exotic annual or biennial grasses or forbs with low cover of perennial species (<10% absolute cover) or stands with a significant perennial herbaceous layer (>10% absolute cover) strongly dominated by exotics (>90% relative cover) with or without annuals and biennials present to dominant. Characteristic understory species include Brassica nigra, Brassica tournefortii, Bromus madritensis, Bromus rubens, Cynodon dactylon, Eragrostis lehmanniana, Erodium cicutarium, Panicum antidotale, Schismus arabicus, Schismus barbatus, and Sorghum halepense with little native composition remaining. Other woody species may include Calliandra eriophylla, Gutierrezia sarothrae, or Isocoma tenuisecta. Gutierrezia microcephala is abundant in some stands. Remnant desert grasses include Aristida ternipes, Bouteloua chondrosioides, Bouteloua curtipendula, Bouteloua eriopoda, Bouteloua rothrockii, Digitaria californica, and Eragrostis intermedia. Other common herbaceous species include Allionia incarnata, Ambrosia confertiflora, Boerhavia erecta, Mollugo verticillata, Cylindropuntia versicolor (= Opuntia versicolor), Panicum hirticaule, Polygala barbeyana, Proboscidea parviflora, and Phemeranthus aurantiacus (= Talinum aurantiacum). Other associated species such as Chenopodium berlandieri, Chloris virgata, Eragrostis cilianensis, Eragrostis pectinacea, Eriochloa acuminata, Ipomoea spp., Kallstroemia grandiflora, Leptochloa panicea ssp. brachiata (= Leptochloa filiformis), Salsola kali, and Solanum elaeagnifolium are often present. The ruderal native annual forb Amaranthus palmeri often dominates or codominates disturbed stands.

Dynamics:  No Data Available
Environmental Description:  This desert grassland group is found in Arizona in areas that were formerly mixed desert grasslands, in northern Mexico, and possibly in New Mexico and Texas. Elevations range from 960-1100 m (3150-3600 feet). Climate is arid to semi-arid with hot summers. Mean annual precipitation ranges from 22-28 cm, but can vary greatly from year to year. Drought is not uncommon. Annual precipitation has bimodal distribution with the proportion of summer precipitation decreasing westward (Barbour and Major 1977). At Tucson, Arizona, about half of the annual rain falls during July to October with the balance during the winter months. The most arid season is late spring and early summer. The summer rain often occurs as high-intensity convective storms. Stands occur on alluvial fans, ridges, hills and valley floors. Sites occur on gentle and moderate slopes to flats and basins that may be intermittently flooded. Substrates are variable and range from well-drained sandy loam to finer-textured silt loam or clays.
Geographic Range: This ruderal desert grassland group occurs in Arizona and possibly New Mexico and Texas in areas that were formerly mixed desert grasslands. It likely occurs in northern Mexico and is presumably widespread in agricultural areas in this warm semi-arid region.

Nations: MX?,US

States/Provinces:  AZ, CA, MXBCN, MXCHH, MXSON?, NM?, NV, TX


Confidence Level: Moderate

Confidence Level Comments: No Data Available
Grank: GNA

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.90 Honey Mesquite / Red Brome - Lehmann''s Lovegrass Desert Ruderal Scrub & Grassland Macrogroup M512 3.A.2.Na.90
Group 3.A.2.Na.90.a Lehmann''s Lovegrass - Red Brome - Asian Mustard Warm Desert Ruderal Grassland Group G677 3.A.2.Na.90.a
Alliance A0878 Cane Cholla Ruderal Cacti Scrub Alliance A0878 3.A.2.Na.90.a
Alliance A2687 Lehmann''s Lovegrass - Weeping Lovegrass Ruderal Desert Grassland Alliance A2687 3.A.2.Na.90.a
Alliance A3873 Crimson Fountaingrass - Buffelgrass Ruderal Grassland Alliance A3873 3.A.2.Na.90.a
Alliance A4081 Bermuda Grass Ruderal Desert Grassland Alliance A4081 3.A.2.Na.90.a
Alliance A4121 Red Brome - Arabian Schismus - Common Mediterranean Grass Ruderal Desert Grassland Alliance A4121 3.A.2.Na.90.a
Alliance A4166 Asian Mustard - African Mustard Ruderal Desert Forbs Alliance A4166 3.A.2.Na.90.a
Concept Lineage: G676 merged into G677 (MSR 7-9-13).

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: No Data Available
Concept Author(s): K.A. Schulz, in Faber-Langendoen et al. (2015)

Author of Description: K.A. Schulz

Acknowledgements: No Data Available

Version Date: 11-06-15
  • Barbour, M. G., and J. Major, editors. 1977. Terrestrial vegetation of California. John Wiley and Sons, New York. 1002 pp.
  • Faber-Langendoen, D., J. Drake, S. Gawler, M. Hall, C. Josse, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, L. Sneddon, K. Schulz, J. Teague, M. Russo, K. Snow, and P. Comer, editors. 2010-2019a. Divisions, Macrogroups and Groups for the Revised U.S. National Vegetation Classification. NatureServe, Arlington, VA. plus appendices. [in preparation]
  • Rodriguez, D., K. G. Sikes, T. Keeler-Wolf, G. Kittel, J. Curtis, C. Curley, and J. Evens. 2017. Vegetation classification of Channel Islands National Park. Report to the National Park Service, Fort Collins, CO.