Rhabdoweisia crenulata Greater Streak-moss

A monoicous acrocarpous moss which grows on shaded, siliceous rock ledges in humid sites in gorges and ravines or on moist north-facing crags. It forms loose, green cushions with long, slightly crisped leaves that are conspicuously toothed in the upper part. The pale brown, egg-shaped capsules are usually abundant and conspicuous. It is an Oceanic Boreo-montane species with a strictly western distribution in Britain. In Wales it is generally scarce and mostly occurs on north-facing cliffs on high ground in mid and north Wales. It is absent from most of south Wales and it is very rare in West Glamorgan with its only known site in Craig y Llyn. Sporophyte capsules are common in summer.