Synonymy

Carex rostrata ‘reedswamp’ Holdgate 1955b p.p.; Lower fens Holdgate 1955Z? p.p.; Mixed fen Holdgate 1955&; Carex rostrata-brovm moss provisional nodum McVean & Ratcliffe 1962, Ferreira 1978; Carex rostrata-Acrocladium sociation Spence 1964 p.p.; Carex nigra-Acrocladium sociation Spence 1964 p.p.; Potentilla-Acrocladium sociation Spence 1964 p.p.; Filipendula-Acrocladium sociation Spence 1964 p.p.; Carex rostrata-Scorpidium scorpioides Association Birks 1973; Potentilla palustris-Acrocladium nodum & related fens Proctor 1974 p.p.; General fen Adam et al. 1975 p.p.; Acrocladio-Caricetum diandrae (Koch 1926) Wheeler 1975 p.p.; Peucedano-Phragmitetum caricetosum Wheeler 1978 p.p.; Acrocladium cuspidatum-Carex diandra mire Ratcliffe & Hattey 1982; Caricetum diandrae Dierssen 1982; Caricetum rostratae Dierssen 1982 p.p.

Constant species

Carex rostrata, Eriophorum angustifolium, Galium palustre, Menyanthes trifoliata, Potentillapalustris, Calliergon cuspidatum.

Rare species

Carex appropinquata, C. diandra, Cicuta virosa, Dactylorhiza traunsteineri, Liparis loeselii, Potamogeton coloratus, Pyrola rotundifolia, Sium latifolium, Utricularia intermedia, Cinclidium stygium.

Physiognomy

The Carex rostrata-Calliergon cuspidatum mire is a community of diverse composition and physiognomy, even within individual stands, but it is generally characterised by a fairly rich assemblage of vascular plants, among which sedges predominate, over a luxuriant carpet of bulky mosses, in which Sphagna are but locally represented. The commonest sedge overall is Carex rostrata and this is quite often abundant, sometimes a sole dominant, particularly in the Campylium-Scorpi- Scorpi dium sub-community. Very frequently, however, it is accompanied here by the nationally rare Continental Northern sedge C. diandra, which has its main locus in Britain in this community and which can likewise be very prominent, especially in the Carex diandra-Calliergon giganteum sub-community. In some stands, one or both of these species are accompanied by a third tall, rhizomatous sedge which can be locally abundant, C. lasiocarpa. When these plants are growing vigorously, they can make up a patchy canopy 60 cm or more high. In some localities, there are also prominent tussocks of C. paniculata or C. appropinquata, though these sedges are scarce in the community as a whole. Other possible local dominants of low frequency throughout are Juncus subnodulosus and Schoenus nigricans and, in a few places, the Car ex-Calliergon mire occurs in some very striking mosaics with the Peucedano-Phragmitetum when a sparse or patchy cover of Phragmites australis or Cladium mariscus can occur (in what Wheeler (1978, 1980a) called Peucedano-Phragmitetum caricetosum).