Synonymy

Carex saxatilis sociation Poore 1955Z?; Carex saxatilis mire McVean & Ratcliffe 1962: Calliergono sarmentosi-Caricetum saxatilis Dierssen 1982.

Constant species

Carex demissa, C. saxatilis, Eriophorum angustifolium, Polygonum viviparum, Thalictrum alpinum, Aneura pinguis, Drepanocladus revolvens, Hylocomium splendens, Scapania undulata.

Rare species

Alchemilla filicaulis ssp. filicaulis, Carex atrofusca, C. microglochin, C. saxatilis, C. vaginata, Juncus biglumis, J. castaneus, Kobresia simpliciuscula.

Physiognomy

Carex saxatilis occurs at low frequency in a variety of wetter vegetation types at high altitudes but here it is typically dominant in a kind of montane mire which has a distinctive assemblage of associates. The sward is generally low, less than 20 cm tall, and often rather open with patchy exposures of soil. Sedges as a group figure quite prominently: apart from C. saxatilis, C. demissa, C. echinata and C. nigra are very frequent and each can be abundant and C. dioica and C. pulicaris also occur occasionally. Such species provide considerable continuity with other more calcicolous mires like the Pinguiculo-Caricetum and lower-altitude stands of the Carici-Saxifragetum but, in contrast to those communities, C. panicea is very scarce here and C. bigelowii is fairly consistent, particularly in grassier transitions to the surrounding swards. As in high-altitude stands of the Carici-Saxifragetum, open stony patches in the vegetation provide a niche for the very rare Arctic-Alpine sedges, C. atrofusca and C. microglochin. C. vaginata has also been recorded in this community.

Apart from Eriophorum angustifolium, a frequent species here which can attain covers of over 10%, almost all the other herbs occur as sparse, scattered individuals. Selaginella selaginoides and Pinguicula vulgaris, both of which are very common, emphasise general similarities with our other calcicolous flushes, but more characteristic are the Arctic-Alpines Thalictrum alpinum, Polygonum viviparum and Juncus triglumis. All these can occur in more montane stands of the Carici-Saxifragetum, together with Saxifraga oppositifolia and S. stellaris, which are scarce to occasional here, but S. aizoides itself is not frequent in the Caricetum saxatilis and, when it does occur, it is typically of low cover. Also rather distinctive is the presence of certain poor-fen herbs like Viola palustris, Caltha palustris and Agrostis canina ssp. canina. Other vascular species recorded occasionally include Leontodon autumnalis, Euphrasia officinalis agg. (including E. scotticd), Geum rivale, Huperzia selago, Ranunculus acris, Rumex acetosa, Alchemilla glabra and the rare A. filicaulis ssp. filicaulis.