Flora of Northern Ireland
Hymenophyllum wilsonii
© Graham Day
Hymenophyllum wilsonii
© Paul Hackney
Hymenophyllum wilsonii
(Map updated: March 2008)
 

This is a small plant which superficially resembles a tuft of moss rather than a fern. The individual leaves are very thin and transparent, and divided into parallel-sided, toothed segments. The sporangia are produced singly inside a two-lipped structure called the indusium at the ends of the leaf-segments. This indusium is untoothed in Wilson's Filmy-fern, but toothed in the much rarer, but otherwise similar, Tunbridge Filmy-fern. The plant is frequent in damp shaded rock crevices such as in block scree in the Mourne Mountains.

All names: Hymenophyllum wilsonii Hook.; Hymenophyllum peltatum auct.; Hymenophyllum unilaterale auct.