Synonymy

Juncus acutiflorus-Acrocladium cuspidatum nodum McVean & Ratcliffe 1962 p.p., Eddy et al. 1969; Juncus acutiflorus pasture Birse & Robertson 1967, 1973; Juncus acutiflorus-Acrocladium cuspidatum sociation Edgell 1969; Species-rich Juncetum effusi Eddy et al. 1969; Juncus acutiflorus-Filipendula ulmaria Association Birks 1973; Juncus articulatus-Acrocladium cuspidatum nodum Prentice & Prentice 1975; Potentillo-Juncetum acutiflori Birse & Robertson 1976, Birse 1980, 1984; Juncus acutiflorus-Sphagnum palustre nodum Adam et al. 1977 p.p.; Galium palustre nodum Daniels 1978 p.p.; Fen communities 27 & 28 Meade 1981; Junco acutiflori-Molinietum (O’Sullivan 1968) Ratcliffe & Hattey 1982 p.p:, Fen meadow Ratcliffe & Hattey 1982 p.p.

Constant species

Galium palustre, Holcus lanatus, Juncus effususlacutiflorus, Lotus uliginosus.

Physiognomy

The Juncus effusus!acutiflorus-Galiumpalustre rush-pasture is a rather ill-defined assemblage of vegetation characterised by the abundance of either Juncus effusus or J. acutiflorus, sometimes both, in a ground of mesophytic herbs of wide occurrence in moister agricultural grasslands. Diversity among the dominants is not very great (nothing like so locally varied as in the Juncus-Cirsium fen-meadow, for example), but the structure of the vegetation can show considerable differences according to the treatment history. And, though the flora is rarely strikingly rich, the associates are quite diverse, both across the whole range of the community and, on a local scale, from site to site and even within large stands. Such variation makes the bounds of this vegetation type hard to fix, both against other rushdominated communities, a problem that is greater towards the east of its distribution, and, increasingly to the west, against grasslands in which Molinia caerulea plays a prominent role.

Of the two rushes which usually dominate here, J. effusus is the commoner throughout, extending across the whole range of the community, though being distinctly more frequent and abundant in the more easterly sub-community through which this vegetation grades imperceptibly to the Holco-Juncetum. J. acutiflorus is much more distinctly western in its occurrence, rivalling or exceeding J. effusus in the other of the sub-communities, which is much more distinctive in its floristics and the usual type of this vegetation which has figured in previous accounts (e.g. McVean & Ratcliffe 1962, Birse & Robertson 1967, 1973,1976, Edgell 1969, Birks 1973, Adam et al. 1977, Ratcliffe & Hattey 1982).