Description: Nearly all plants of Asplenium trichomanes encountered in Ireland will be the tetraploid subspecies quadrivalens, which is very abundant. The diploid subspecies trichomanes is generally smaller (although stunted forms of subsp. quadrivalens can be of similar size) and the spores are smaller when measured under the microscope. It is a much rarer plant, being currently known only from two sites within Northern Ireland, both are on shale rock outcrops in the Mourne Mountains. Two other sites occur in the Republic of Ireland.

All names: Asplenium trichomanes ssp. trichomanes

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

iNaturalist: Asplenium trichomanes ssp trichomanes at iNaturalist World Species Observations database.