The vegetation is dominated by grasses and herbaceous plants, growing on soils deficient in lime (calcium). These may be found on acid sedimentary rock such as sandstone; acid igneous rock such as granite; and fluvial or glacial deposits such as sand and gravel. Typical plants of lowland acid grassland in Britain include common bent grass, Agrostis capillaris, wavy hair-grass, Deschampsia flexuosa, bristle bent grass, Agrostis curtisii, tormentil, Potentilla erecta, and flowers such as sheep's sorrel, Rumex acetosella and heath bedstraw, Galium saxatile.[1]