Scientific name Carex rostrata swamp/fen
Common name Bottle Sedge swamp/fen
Community code FW3C


FW3C: Carex rostrata swamp/fen   FW3C: Carex rostrata swamp/fen   FW3C map: Carex rostrata swamp/fen

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This community consists of glaucous, usually dense beds of Carex rostrata. No other species is more than occasional in the community as a whole, therefore further details on the vegetation are described under sub-communities.



This vegetation type occurs around the margins of mesotrophic and slightly dystrophic lakes and pools. Stands have also been recorded in turloughs. It may also be found in poor fens and in upland flushes amongst blanket bog and wet heath.



Two distinct sub-communities are described. In the Phragmites australis – Equisetum fluviatile sub-community (FW3Ci) of mesotrophic lakes, Carex rostrata, growing in standing water, may be the only species present. Some sparse cover of Phragmites australis is frequent, however. Equisetum fluviatile is occasionally present but can be abundant. Less often found are Typha latifolia, Mentha aquatica, Menyanthes trifoliata and Schoenoplectus lacustris. In the rarer Sphagnum cuspidatum – Warnstorfia fluitans sub-community (FW3Cii) of acidic fens and flushes, Carex rostrata, and frequently Juncus effusus, grow through a quaking carpet of Sphagnum cuspidatum, more rarely containing Sphagnum subsecundum agg. or Sphagnum squarrosum. In this bryophyte layer may also be encountered the long shoots of Warnstorfia fluitans or some cover of Polytrichum commune, Aulacomnium palustre and Campylopus introflexus.


Similar communities

Sub-community FW3Ci is related to the FE2D Carex rostrata – Menyanthes trifoliata mire community. In that assemblage, however, Menyanthes trifoliata and other marsh and fen species, such as Galium palustre, Potentilla palustris, Agrostis stolonifera and Hydrocotyle vulgaris, are more likely to be recorded. Some confusion could arise between FW3Cii and the FE2E Menyanthes trifoliata – Sphagnum recurvum agg. mire, which also combines Carex rostrata with high Sphagnum cover, but in the present community Menyanthes and Sphagnum recurvum agg. are typically absent.


Conservation value

This is a species-poor community in terms of plants. However, some examples of sub-community FW3Ci form part of the priority EU HD Annex I habitat 3180 Turloughs*. Stands of FW3Cii are likely to correspond to habitat 7140 Transition mires. In addition, the EU HD Annex II species Desmoulin’s whorl snail (Vertigo moulinsiana) has been recorded from multiple stands of this vegetation.



This community is typically unmanaged. Threats include eutrophication and drainage.