[1] In the United Kingdom calaminarian grassland is regarded as one of its 'habitats of principal importance for biodiversity conservation' and is predominantly found on industrial or post-industrial land, especially in the east of Cumbria and western dales, the Peak District[2] and north west Wales and parts of the Scottish Highlands.
Some examples include Cwmystwyth in West Wales, Halkyn Mountain in Flintshire, Upper Teesdale in County Durham, Oxclose in Tyne and Wear, Caenlochan in eastern Scotland, the Isle of Rhum in western Scotland [3] and Keen of Hamar in Shetland.
[3] Species typical of Calaminarian grasslands include spring sandwort (Minuartia verna), field pennycress (Thlaspi arvense), genetically adapted races of species such as thrift (Armeria maritima) and bladder campion (Silene uniflora).
Other notable species include Young's helleborine (Epipactis youngiana), forked spleenwort (Asplenium septentrionale), Cornish path-moss (Ditrichum cornubicum), western rustwort (Marsupella profunda), Cephaloziella nicholsonii, Ditrichum plumbicola, Scottish sandwort (Arenaria norvegica) and Shetland mouse-ear (Cerastium nigrescens).
These include northern rock-cress (Arabis petraea), forked spleenwort (Asplenium septentrionale) and Young’s helleborine (Epipactis youngiana).