Hymenophyllum wilsonii Wilson's Filmy-fern

Hymenophyllum wilsonii, Wilson's Filmy-fern, is very similar to Tunbridge Filmy-fern (Hymenophyllum tunbrigense) and is best distinguished from it by the structure of its sporangia, which have a smooth border (see description and photos of Tunbridge Filmy-fern). It is an Atlantic species which is more widespread and frequent than Tunbridge Filmy-fern in Britain. It is also much more likely to be encountered in mountainous areas where it forms mossy cushions on vertical rock faces and the boles of trees. It is very scarce in West Glamorgan where the only known population is on the north-facing scarp of Craig y Llyn.

Native