Marchesinia mackaii MacKay's Pouncewort

A large, dark coloured, autoicous leafy liverwort which grows closely appressed to calcareous rocks, often on vertical surfaces. The colonies present a striking contrast against white limestone rock and are almost instantly recognisable. It is an Oceanic species which is locally frequent in Britain with an extreme western distribution. Its distribution in Wales is largely coastal and in West Glamorgan it is mostly restricted to limestone rocks in Gower, sometimes in relativey exposed surfaces on the coast, but also on limestone boulders in shaded parts of Gower's Ash woodlands. There are isolated occurrences in the Vale of Neath. Sporophyte capsules and perianths are common.