Synonymy

Includes Trifolium occidentale-Herniaria ciliolata-Catapodium marinum and Trifolium occidentale-Scilla autumnalis-Jasione montana noda Coombe 1961; Sagino-Catapodietum marinae R. Tx. & Westhoff 1963; Thero-Sedetum anglici Malloch 1971; Sedion anglici communities Proctor 1975.

Constant species

Armeria maritima, Plantago coronopus, Festuca rubra, Cerastium diffusum ssp. diffusum, Sedum spp. (S. anglicum and S. acre).

Rare species

Allium schoenoprasum, Astragalus danicus, Brassica oleracea, Centaurium capitatum, Genista pilosa, Herniaria ciliolata, Lotus hispidus, Mibora minima, Minuartia verna, Ononis reclinata, Ornithopus pinnatus, Poa bulbosa, P. infirma, Polycarpon tetraphyllum, Romulea columnae, Scilla autumnalis, S. verna, Senecio integrifolius ssp. maritimus, Trifolium occidental, T. suffocatum.

Physiognomy

The Armeria-Cerastium community has a very short open turf in which cushions of A. maritima, tussocks of rather poorly-growing F. rubra, P. coronopus or Sedum spp. may dominate. Sprawling plants of C. diffusum ssp. diffusum occur throughout and the annual grasses Desmazeria marina and Bromus hordeaceus ssp. ferronii are frequent. Numerous winter annuals flourish on the patches of bare ground and many of these are national rarities. Trifolium spp. of restricted distribution are also characteristic of some sub-communities. Bryophytes occur at low frequencies throughout but in some sub-communities they and lichens may attain up to 20% cover.

Sub-communities

Desmazeria marina sub-community: Sagino-Catapodietum marinae R. Tx. & Westhoff 1963 p.p. In this, the most species-poor of the sub-communities, A. maritima and either F. rubra or D. marina tend to co-dominate with scattered plants of C. diffusum ssp. diffusum, B. hordeaceus ssp. ferronii and Spergularia rupicola.