Synonymy

Bryophyte flushes Pigott 1956a p.p..; Carex panicea-Campylium stellatum nodum McVean & Ratcliffe 1962p.p.; Cratoneuron-Carex nigra nodum Eddy et al. 1969; Carex nigra-Equisetum palustre nodum Huntley 1979 p.p.; Saxifraga aizoides-Tussilago farfara nodum Huntley 1979 p.p.; Saxifraga aizoides-Juncus triglumis nodum Huntley 1979 p.p.

Constant species

Agrostis canina, Cardamine pratensis, Carex demissa, C. nigra, C. panicea, Festuca rubra, Leontodon autumnalis, Polygonum viviparum, Selaginella selaginoides, Trifolium repens, Bryum pseudotriquetrum, Cratoneuron commutatum, C. filicinum, Philonotis fontana.

Rare species

Epilobium alsinifolium, E. nerteroides, Saxifraga hirculus, Oncophorus virens.

Physiognomy

While the Cratoneuron commutatum-Carex nigra spring preserves the same pattern of generally overwhelming dominance by Cratoneuron commutatum (again occasionally supplemented or replaced by C. filicinum) as in the Cratoneuron-Festuca community, the associated flora here is very much richer. This is partly to be seen among the bryophytes, where a variety of other species finds frequent or occasional representation in the mat, though not generally with very much abundance. Bryum pseudotriquetrum, however, and Philonotis fontana, which are the commonest among these plants, can have moderately high cover and there are many companions which can occur locally as quite prominent patches: Aneura pinguis, Plagiomnium elatum, Fissidens adianthoides, Philonotis calcarea, Ctenidium molluscum, Rhizomnium pseudopunctatum, Campylium stellatum, Drepanocladus revolvens and Cinclidium stygium. Among rarer species, the community also provides a locus for Oncophorus virens and Meesia uliginosa.

But it is among the vascular element that the increasedrichness of the vegetation is most evident, for here a large number of species make a frequent, even if usually low-cover, contribution. Small sedges are particularly noticeable, with Carex demissa, C. nigra and C. panicea constant, C. pulicaris, C. flacca and C. dioica also common. The first three in particular can be quite abundant and, when present in fairly extensive mixtures, these sedges can bring the vegetation close to a Caricion davallianae mire in its structure and composition. Then, there are frequent scattered plants of Cardamine pratensis, Selaginella selaginoides, Leontodon autumnalis, Polygonum viviparum, Trifolium repens, Cirsium palustre, Ranunculus flammula, Sagina nodosa, Juncus triglumis, J. articulatus, J. bulbosus, Cerastium fontanum, Prunella vulgaris, Caltha palustris (often in its diminutive montane form), Galium palustre, Equisetum palustre, Achillea ptarmica, Cochlearia officinalis (often recorded as ssp. alpina), Triglochin palustris, Ranunculus acris, Anthoxanthum odoratum, Festuca ovina, Epilobium anagallidifolium and, in northern England, where it has become very much at home on wet stony ground, the New Zealand introduction E. nerteroides.