Carex nudata Herbaceous Alliance
Torrent sedge patches

USDA Ecological Section Map

Summary Information

  • Primary Life FormHerb
  • Elevation0-1500 m
  • State RarityS3
  • Global RarityG3
  • DistributionUSA: CA, OR, WA (TJM2)
  • Endemic to CaliforniaNo
  • Endemic to California Floristic Province and DesertsNo
  • Date Added2009/09/01

Characteristic Species

Carex nudata is dominant in the herbaceous layer with Artemisia douglasiana, Artemisia ludoviciana, Carex praegracilis, Carex senta, Carex serratodens, Cyperus eragrostis, Darmera peltata, Datisca glomerata, Equisetum arvense, Equisetum hyemale, Mimulus guttatus, Paspalum dilatatum, Poa pratensis and Stachys stricta. Emergent riparian trees may be present at low cover, especially Alnus spp., Populus spp. or Salix spp.

Vegetation Layers

Herbs < 2 m; cover is open to continuous.

Membership Rules

  • Carex nudata > 50% relative cover in the herbaceous layer; trees and shrubs < 10% cover (Potter 2005).
  • Carex nudata > 50% relative cover with other herbs lower in cover including Equisetum spp. and Woodwardia fimbriata along rocky streams and streambanks (Buck-Diaz et al. 2021, Sikes et al. 2021, Sikes et al. 2023).


Bouldery and rocky streams below the high-water mark. Soils are sandy alluvium. The USFWS Wetland Inventory (1996 national list) recognizes Carex nudata as a FACW plant.

Other Habitat, Alliance and Community Groupings

MCV (1995) Sedge series
NVCS (2009) Not treated
Calveg Wet grasses and forbs
Holland White alder riparian forest
Munz Freshwater marsh
WHR Montane riparian, Valley foothill riparian
CDFW CA Code 45.182.00

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 America Wet Meadow and Low Shrub Carr
Group Californian warm temperate marsh/seep