Status in Britain: Nationally Scarce
Additional: European Red Data Book; Key Biodiversity Species; Near Endemic to Britain.

Only known from three sites in Wales. Elsewhere in the British Isles it only occurs with any degree of frequency in parts of Western Scotland. Outside of Britain it is known from only one site in France, so is almost endemic. It grows in humid broadleaf woodland where there is a high degree of humidity, usually on rock outcrops and boulders.