Carex (pansa, praegracilis) Herbaceous Alliance
Sand dune sedge swaths

USDA Ecological Section Map

Summary Information

  • Primary Life FormHerb
  • Elevation0-250 m
  • State RarityS3?
  • Global RarityG4?
  • DistributionCAN: BC. USA: CA, OR, WA (USDA Plants)
  • Endemic to CaliforniaNo
  • Endemic to California Floristic Province and DesertsNo
  • Date Added2009/09/01

Characteristic Species

Carex pansa or Carex praegracilis is dominant or co-dominant in the herbaceous layer with Achillea millefolium, Artemisia pycnocephala, Briza maxima, Camissonia cheiranthifolia, Cardionema ramosissimum, Carpobrotus chilensis, Distichlis spicata, Erigeron glaucus, Juncus effusus, Juncus patens, Lotus spp., Plantago ovata var. insularis, Poa douglasii and Pteridium aquilinum. Emergent shrubs may be present at low cover, including Baccharis pilularis or Lotus scoparius.

Vegetation Layers

Herbs < 50 cm; cover is open to continuous.

Membership Rules

  • Carex pansa or Carex praegracilis is > 30% relative cover in the herbaceous layer (Klein et al. 2015, Rodriguez et al. 2017).


Swales of coastal sand dunes, coastal terraces, and moist places near the coast. Soils are seasonally and tidally flooded. The USFWS Wetland Inventory (2012 national list) recognizes Carex pansa as a FACU/FAC plant and Carex praegracilis as a FACW plant.

Other Habitat, Alliance and Community Groupings

MCV (1995) Sedge series
NVCS (2009) Not treated
Calveg Dunes, Wet grasses and forbs
Holland Active coastal dunes, Northern foredunes, Southern foredunes, Coastal and valley freshwater marsh
Munz Coastal strand, Freshwater marsh
WHR Coastal scrub, Wet meadow
CDFW CA Code 45.184.00

National Vegetation Classification Hierarchy

Formation Class Mesomorphic Shrub and Herb Vegetation (Shrubland and Grassland)
Formation Subclass Temperate and Boreal Shrubland and Grassland
Formation Temperate and Boreal Freshwater Marsh
Division Western North American Freshwater Marsh
Macro Group Western North American Freshwater Marsh
Group Vancouverian coastal/tidal marsh and meadow