Synonymy

Caricetum Pearsall 1920 p.p.; Carex vesicaria-Veronica scutellata sociation Spence 1964

Constant species

Carex vesicaria, Equisetum fluviatile, Galium palustre.

Rare species

Carex aquatilis.

Physiognomy

The Caricetum vesicariae is almost always dominated by Carex vesicaria, the tufted shoots of which form an open or closed cover in which there is usually a little emergent Equisetum fluviatile, some scrambling Galium palustre and sometimes abundant Juncus effusus. Indeed, although few other species are frequent throughout, the general appearance of the vegetation is often more like a fen than a swamp.

Sub-communities

Carex vesicaria sub-community. Here are included those rare stands in which C. vesicaria forms a virtually pure and sometimes extensive cover.

Mentha aquatica sub-community. In this sub-community, the C. vesicaria has an understorey of small or scrambling herbs such as Mentha aquatica, Myosotis scorpioides, Galium palustre and, particularly distinctive, Veronica scutellata. There is also usually some Equisetum fluviatile and Juncus effusus and scattered tall herbs such as Filipendula ulmaria, Lythrum salicaria and, sometimes abundantly, Phalaris arundinacea. A variety of other poor-fen and swamp species occur occasionally or rarely, including Carex aquatilis.

Carex rostrata sub-community. The vegetation here is somewhat similar to that of the Mentha sub-community except that Carex rostrata, Potentilla palustris and Menyanthes trifoliata are frequent and sometimes abundant components. Carex aquatilis has also been recorded from this sub-community.

Habitat

The community occurs in open-water transitions on mesotrophic inorganic or peaty substrates of pH 6.0-6.8 around lakes and in slow-moving or standing waters of streams and dykes. The Carex vesicaria and Carex rostrata sub-communities are characteristic of deeper standing waters, up to about 40 cm, whereas the Mentha sub-community typically occurs in drier situations where the water-table varies between 10 cm below and 20 cm above ground. The vegetation is sometimes cattle-grazed.

Zonation and succession

Although stands of the Carex vesicaria sub-community can occur in standing open water, the usual position of the community in marginal zonations is for it to occur inshore of the Caricetum rostratae to which it may grade through the Carex rostrata sub-community. Around such higher reaches and along the banks of dykes, the Mentha sub-community may occur alongside or pass to the Phragmitetum australis or to the Phalaridetum arundinaceae.