Description: This is an extremely rare fern which may be extinct now in Northern Ireland. It is closely related to Asplenium adiantum-nigrum but differs from that very common species by having smaller spores and narrower segments to the leaf, so that it looks more delicate. It is only known from one site near Newtownards where it has not been seen since 1946. Similar-looking plants grow on the cliffs of Binevenagh but are in fact forms of Asplenium adiantum-nigrum.

All names: Asplenium onopteris L.; Asplenium adiantum-nigrum ssp. onopteris (L.) Heufler

Distribution Map from NBN: Asplenium onopteris at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Asplenium onopteris at iNaturalist World Species Observations database.