Common (Translated Scientific) Name: Velvet Mesquite / Carelessweed Wet Scrub
Hierarchy Level: Association
Type Concept: This riparian woodland is described from southern Arizona. Plot data from Buenos Aires National Wildlife Refuge indicate an elevational range of 915-1090 m (3000-3570 feet) and that stands are found on flats and gentle slopes along drainages and in floodplains on valley floor. Soils are sandy loam or loam. Sites are typically disturbed. The vegetation is characterized by a moderately dense to dense tree canopy dominated or codominated by Prosopis velutina and with Amaranthus palmeri strongly dominating the moderately dense to dense herbaceous layer. Scattered short shrubs may be present but are generally not dense enough to form strata. Common herbaceous species include Ambrosia confertiflora, Ambrosia psilostachya, Bouteloua aristidoides, Chloris virgata, Eragrostis intermedia, Ipomoea hederacea, Sporobolus airoides, and Tidestromia lanuginosa. If present, Eragrostis lehmanniana cover is low, with less than 25% cover and less than a third of the total perennial graminoid cover.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features:
Classification Comments: If a Prosopis velutina- and Acacia greggii-codominated stand has an understory dominated by Amaranthus palmeri or Sorghum halepense, it should be classified by the understory dominance.
Similar NVC Types:
Physiognomy and Structure: No Data Available
Floristics: The vegetation is characterized by a moderately dense to dense tree canopy codominated by Prosopis velutina and Acacia greggii. Scattered short shrubs may be present but are generally not dense enough to form strata. Common shrubs may include Baccharis emoryi, Baccharis sarothroides, Calliandra eriophylla, Celtis pallida, Lycium andersonii, Mimosa aculeaticarpa var. biuncifera (= Mimosa biuncifera), Mimosa dysocarpa, and Opuntia spinosior. The open to dense (20-80% cover) herbaceous layer is dominated by a mixture of grasses and forbs. The native annual forb Amaranthus palmeri may be present but does not codominate the herbaceous layer. Associated herbaceous species include Aristida ternipes, Boerhavia spp., Bouteloua aristidoides, Bouteloua curtipendula, Chloris virgata, Digitaria californica, Ipomoea hederacea, Kallstroemia grandiflora, Panicum hirticaule, Proboscidea parviflora, and Tidestromia lanuginosa. If present, Eragrostis lehmanniana cover is low, with less than 25% cover and less than a third of the total perennial graminoid cover.
Dynamics: No Data Available
Environmental Description: This riparian woodland is described from southern Arizona. Plot data from Buenos Aires National Wildlife Refuge indicate an elevational range of 970-1030 m (3200-3700 feet) where it is found on gentle slopes along drainages and in floodplains on valley floors. The alluvial soils are variable and range from sand to clay textures.
Geographic Range: This shrubland is found on foothills of Buenos Aires National Wildlife Refuge in southern Arizona and likely occurs in Texas and northern Mexico.
Nations: MX, US
States/Provinces: AZ, MXCH, MXCO, MXSO, NM, TX
|US Forest Service Ecoregions (1994/1995)|
Chihuahuan Semi-Desert Province
Confident or certain
Basin and Range Section
Confident or certain
Confidence Level: Low - Poorly Documented
Confidence Level Comments:
Synonomy: = Prosopis velutina / Amaranthus palmeri Woodland (Schulz 2004)
Concept Author(s): K.A. Schulz
Author of Description: K.A. Schulz
Version Date: 22Aug2007
- Schulz, K. A. 2004. Vegetation classification of Buenos Aires National Wildlife Refuge, Arizona. Unpublished report submitted to USDI Fish and Wildlife Service. NatureServe, Western Regional Office, Boulder, CO.
- Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.