This small, short stemmed fern is frequently found in rock-crevices, on the mortar of old stone walls and alkaline rocks, usually growing on vertical surfaces. Its dull, dark evergreen leaves are thick and in irregular tufts, up to 10cm long and bi- or tripinnate. The petiole is often longer than the leaf-blade. The groups of spore-producing structures (sori) on the underside of the leaflets are detectable from June to October. This is a native plant which belongs to the family Aspleniaceae.
I first recorded this plant in the Burren, Co Clare in 1988 and photographed it there in 2006.
If you are satisfied you have correctly identified this plant, please submit your sighting to the National Biodiversity Data Centre