Carex (aquatilis, lenticularis) Herbaceous Alliance
Water sedge and lakeshore sedge meadows

USDA Ecological Section Map

Summary Information

  • Primary Life FormHerb
  • Elevation1200-3400 m
  • State RarityS3
  • Global RarityG5
  • DistributionCAN: AB, MB, NB, ON, QC. USA: AZ, CA, CO, ID, MI, MN, MT, ND, NM, NV, OR, SD, UT, WA, WY (NatureServe)
  • Endemic to CaliforniaNo
  • Endemic to California Floristic Province and DesertsNo
  • Date Added2009/09/01

Characteristic Species

Carex aquatilis and/or Carex lenticularis is dominant or co-dominant in the herbaceous layer with Achillea millefolium, Bistorta bistortoides, Carex jonesii, Carex luzulina, Carex microptera, Carex simulata, Carex utriculata, Deschampsia cespitosa, Dodecatheon jeffreyi, Eleocharis quinqueflora, Epilobium ciliatum, Hypericum anagalloides, Juncus arcticus, Mimulus primuloides, Muhlenbergia filiformis, Oreostemma alpigenum, Perideridia parishii, Phleum alpinum, Phleum pratense, Poa pratensis, Poa secunda, Rumex crispus, Scirpus congdonii, Taraxacum officinale and Viola macloskeyi. Emergent trees and shrubs may be present at low cover: such as Pinus contorta ssp. murrayana Cornus sericea, Kalmia microphylla, Salix spp. and Vaccinium uliginosum. Mosses may be abundant, including Aulacomnium palustre and Campylium stellatum

Vegetation Layers

Emergent trees, if present, are sparse. Herbs < 1.5 m; cover is open to continuous.

Membership Rules

  • Carex aquatilis or C. lenticularis is ≥ 30% relative cover in the herbaceous layer; C. scopulorum, C. utriculata, or C. vesicaria absent or at relatively low cover (Potter 2005).
  • Carex aquatilis and/or C. lenticularis has ≥ 30% relative cover in the herbaceous layer; no other Carex spp. has greater cover (Boul et al. 2021b).


Wet meadows in basins, shallow lakes and margins, floodplains; montane fens; and along streams in narrow riparian ecotones. Soils have high organic material content; some are sandy. The USACE Wetland Inventory (2018 national list) recognizes Carex aquatilis and C. lenticularis as OBL plants.

Other Habitat, Alliance and Community Groupings

MCV (1995) Sedge series
NVCS (2009) Carex aquatilis seasonally flooded herbaceous alliance
Calveg Wet grasses and forbs, Tule-Cattail
Holland Wet montane meadow, Wet subalpine or alpine meadow, Freshwater seep, Fen
Munz Freshwater marsh
WHR Wet meadow
CDFW CA Code 45.168.00

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 Western Cordilleran montane-boreal summer-saturated meadow