The Collaborative International Dictionary
Asplenium trichomanes
maidenhair spleenwort \maidenhair spleenwort\ n. A small rock-inhabiting fern ( Asplenium trichomanes) of the North temperate zone and Hawaii, having pinnate fronds.
Wikipedia
Asplenium trichomanes
Asplenium trichomanes (commonly known as maidenhair spleenwort) is a small fern in the spleenwort genus Asplenium. It is a widespread and common species, occurring almost worldwide in a variety of rocky habitats. It is a variable fern with several subspecies.