Synonymy

Vaccinietum myrtilli Smith 1900, Lewis & Moss 1911, Tansley 1939, Fidler et al. 1971; Vaccinium-xïàgQ & Kzccmzwm-summit Smith & Moss 1903, Smith & Rankin 1903; Gr amino-Vaccine turn Smith 1911b; Vaccinium-edge Moss 1913; Empetreto-Vaccinetum Burges 1951 p.p.; Lichen-rich Vaccinium-Festuca association Poore 19556; Vaccinium-Chamaepericlymenum nodum Poore & McVean 1957 p.p.; Vaccineto-Empetretum McVean & Ratcliffe 1962; Festuceto-Vaccinetum McVean & Ratcliffe 1962, Evans et al. 1977, Ferreira 1978; Festuca ovinaiDeschampsia flexuosa grassland King 1962 p.p.; Vaccinium myrtillus- heath moss sociation Edgell 1969; Mountain Vaccinium heaths Gimingham 1972p.p.; Phyllodoce caerulea sites Coker & Coker 1973 p.p.; Huperzio-Vaccinetum Hill & Evans 1978; Rhytidiadelphus loreus-Vaccinium myrtillus community Birse 1980.

Constant species

Deschampsia flexuosa, Galium saxatile, Vaccinium myrtillus, Dicranum scoparium, Pleurozium schreberi.

Rare species

Loiseleuria procumbens, Minuartia sedoides, Phyllodoce caerulea, Salix lapponum, Barbilophozia lycopodiodes, Scapania ornithopodiodes.

Physiognomy

The Vaccinium myrtillus-Deschampsia flexuosa heath includes a variety of moss-rich and grassy sub-shrub vegetation in which Vaccinium myrtillus is the most frequent and generally the most abundant ericoid, with Calluna vulgaris typically having a rather inconspicuous role: heather is usually only occasional here and present as scattered plants that are often noticeably lacking in vigour. V. myrtillus is not always truly dominant, however, and other sub-shrubs sometimes make a sizeable contribution to the canopy, which is generally 1-2 dm tall, occasionally rather open and, even where extensive, is without that uniform density of growth found in heaths with much young Calluna. Most frequent among the associated sub-shrubs is Empetrum nigrum, usually ssp. hermaphroditum where it has been possible to distinguish the taxa, though sometimes clearly ssp. nigrum, and occasionally both plants growing together. Typically, the procumbent stems of the crowberry penetrate quite far among the bilberry, branching out into patches which can be locally abundant. Some of the vegetation subsumed here has co-dominant E. nigrum as in the various kinds of Vaccinio-Empetretum described by Burges (1951) and McVean & Ratcliffe (1962), and, of course, being evergreen, the crowberry catches the eye more than the deciduous bilberry in stands without a covering of winter snow.

V. vitis-idaea is about as common as E. nigrum, though typically much less abundant. V. uliginosum, on the other hand, is rather scarce and preferential for one sub-community but it can have locally high cover there, even attaining co-dominance in some stands (Poore & McVean 1957,