Carex densa Provisional Herbaceous Alliance
Dense sedge marshes
Dense sedge marshes
- Primary Life FormHerb
- Elevation0-1500 m
- State RarityS2?
- Global RarityG2?
- DistributionUSA: CA, OR, WA (TJM2)
- Endemic to CaliforniaNo
- Endemic to California Floristic Province and DesertsNo
- Date Added2009/09/01
Carex densa is dominant or co-dominant in the herbaceous layer with Avena barbata, Carex praegracilis, Dipsacus sativus, Geranium dissectum, Holcus lanatus, Juncus spp., Lolium perenne, Mentha pulegium, Ranunculus californicus, Wyethia glabra and Zigadenus micranthus. Emergent shrubs may be present at low cover, including Baccharis pilularis.
Herbs < 1 m; cover is continuous.
Saturated bottomlands and flats, freshwater seeps. Soils are silty to sandy, and seasonally or intermittently saturated. The USFWS Wetland Inventory (1996 national list) recognizes Carex densa as an OBL plant.
Other Habitat, Alliance, and Community Groupings
|MCV (1995)||Not treated|
|NVCS (2009)||Not treated|
|Calveg||Wet grasses and forbs|
|WHR||Fresh emergent wetland|
|CDFW CA Code||45.165.00|
Carex densa grows from cismontane California to Washington in seasonally wet and riparian sites. Its wrinkled leaf sheaths sometimes appear spotted. Its inflorescences are clustered as head-like spikes with pistillate spikelets that are brown with lighter, ciliate margins. C. densa is widely variable and has been subdivided into as many as four species (Ball and Reznicek 2002).
A few stands sampled at Mount Tamalpais in Marin Co. on the Northern California Coast (263A) include a variety of wetland plants (Evens and Kentner 2006). Evens and Kentner proposed two provisional associations: the Carex densa-Juncus xiphioides and the Carex densa-Lolium perenne-Juncus spp. associations. Other stands in the region included Festuca arundinacea and other native herbs at low cover. A few other stands have been sampled in the southern Sierra Nevada (M261Er) in the Piute Mountains (VegCAMP 2015a). The relationships between this and other wetland alliances need further evaluation, and we need more sampling and analysis to better characterize this alliance.
-  Evens, J.M.;Kentner, E. 2006
-  Buck-Diaz, J.;Sikes, K.;Evens, J.M. 2020
- VegCAMP (Vegetation Classification and Mapping Program), 2015a