Washingtonia filifera Woodland Alliance
California fan palm oasis

USDA Ecological Section Map

Summary Information

  • Primary Life FormTree
  • Elevation100-900 m
  • State RarityS3.2
  • Global RarityG3
  • DistributionUSA: AZ, CA, NV. Mexico (NatureServe)
  • Endemic to CaliforniaNo
  • Endemic to California Floristic Province and DesertsYes
  • Date Added1995/11/01

Characteristic Species

Washingtonia filifera is dominant or co-dominant in the tree canopy with Alnus rhombifolia, Fraxinus velutina, Platanus racemosa, Populus fremontii, Prosopis glandulosa, Prosopis pubescens, Salix exigua, Salix gooddingii and Salix lasiolepis. Shrubs include Atriplex spp., Baccharis emoryi, Encelia farinosa, Pluchea sericea, Suaeda moquinii or Tamarix spp.

Vegetation Layers

Trees < 30 m; canopy is open to continuous. Shrub layer is open to intermittent. Herbaceous layer is open to continuous.

Membership Rules

  • Washingtonia filifera > 3% absolute cover in the tree canopy (Keeler-Wolf et al. 1998b).


Desert springs in canyon waterways or along fault lines where underground water is continuously available. The USFWS Wetland Inventory (1996 national list) recognizes Washingtonia filifera as a FACW plant.

Other Habitat, Alliance and Community Groupings

MCV (1995) Fan palm series
NVCS (2009) Washingtonia filifera seasonally flooded woodland alliance
Calveg Fan palm
Holland Desert fan palm oasis woodland
Munz Creosote bush scrub
WHR Palm oasis
CDFW CA Code 61.520.00

National Vegetation Classification Hierarchy

Formation Class Mesomorphic Tree Vegetation (Forest and Woodland)
Formation Subclass Temperate Forest
Formation Temperate Flooded and Swamp Forest
Division Western North America Warm Temperate Flooded and Swamp Forest
Macro Group Southwestern North American Riparian, Flooded and Swamp Forest
Group Southwestern North American riparian evergreen and deciduous woodland