Dicoria canescens - Abronia villosa - Panicum urvilleanum Sparsely Vegetated Alliance
Mojave-Sonoran desert dunes

USDA Ecological Section Map

Summary Information

  • Primary Life FormHerb
  • Elevation10-1300 m
  • State RarityS3.2
  • Global RarityG4
  • DistributionUSA: CA. Mexico (NatureServe)
  • Endemic to CaliforniaNo
  • Endemic to California Floristic Province and DesertsNo
  • Date Added2017/02/10

Characteristic Species

Abronia villosa, Dicoria canescens, Panicum urvilleanum and/or Swallenia alexandrae is characteristically present in the herbaceous and subshrub layers with Achnatherum hymenoides, Aliciella latifolia ssp. latifolia, Argemone corymbosa, Astragalus lentiginosus, Camissonia claviformis, Cleome sparsifolia, Croton californicus, Cryptantha spp., Eriogonum spp., Geraea canescens, Helianthus annuus, Oenothera californica ssp. eurekensis, Oenothera deltoides, Palafoxia arida, Pleuraphis jamesii, Pleuraphis rigida, Rumex hymenosepalus, Salsola tragus, Schismus spp., Tiquilia plicata and/or Wislizenia refracta. Emergent shrubs may be present at low cover, including Ambrosia dumosa, Atriplex canescens, Atriplex polycarpa, Eriogonum deserticola, Larrea tridentata, Penstemon thurberi, Petalonyx thurberi or Suaeda moquinii.

Vegetation Layers

Herbs and subshrubs < 1 m; cover is sparse to intermittent with seasonal annuals and scattered perennials.

Membership Rules

  • Scattered plants with a combined absolute cover of usually > 2% and < 10% in the herbaceous layer; Achnatherum hymenoides, Ambrosia dumosa, Larrea tridentata, Pleuraphis rigida < 2% absolute cover (cf. Thomas et al. 2004).
  • Swallenia alexandrae characteristically present in the herbaceous layer (Thomas et al. 2004, Evens et al. 2014).
  • Panicum urvilleanum > 2% absolute cover (Thomas et al. 2004).
  • Plants sparse to abundant, depending on annual rainfall, and characterized by grasses, such as Panicum urvilleanum or Swallenia alexandrae, or annual and perennial forbs such as Dicoria canescens, Abronia villosa, Croton californicus, Oenothera deltoides, or others (Evens et al. 2014).
  • Petalonyx thurberi > 50% relative cover in an open shrub canopy (Evens et al. 2014).
  • Wislizenia refracta > 50% relative cover in the herbaceous layer (Evens and Hartman 2007, VegCAMP and AIS 2013).


Active dunes, partially stabilized dunes, stabilized dunes, sand fields. Soils are fine to moderately coarse sand.

Other Habitat, Alliance and Community Groupings

MCV (1995) Desert sand-verbena series
NVCS (2009) Abronia villosa sparsely vegetated alliance
Calveg Dunes
Holland Active desert dunes, Stabilized and partially stabilized dunes, Stabilized and partially stabilized desert sand fields
Munz Creosote bush scrub
WHR Desert scrub
CDFW CA Code 22.105.00

National Vegetation Classification Hierarchy

Formation Class Lithomorphic Vegetation (Nonvascular and Sparse Vascular Rock Vegetation)
Formation Subclass Semi-Desert Nonvascular and Sparse Vascular Vegetation
Formation Warm Semi-Desert Cliff, Scree, and Rock Vegetation
Division North American Warm Semi-Desert Cliff, Scree, and Rock Vegetation
Macro Group North American Warm Semi-Desert Cliff, Scree, and Other Rock Vegetation
Group North American warm desert dunes and sand flats