This moss occurs on limestone rocks and walls at scattered locations on the South coast of Wales, and on the coast of the island of Anglesey in the North. It is predominantly a Mediterranean species and is at its northern limit in the British Isles. Its leaves are triangular, with a strong nerve and a toothed margin. They are closely adpressed to the stem (imbricate) when dry but spreading when wet,so that the plant has a quite different appearance in each of these states (see inset)