Polypodium vulgare L.

It’s relatively easy to find his fern colonizing the rock fissures or between the stones of a drywall, although with a shady and wet aspect. It is also very easy to recognize this plant by its linear lobed leave, which become smaller as you go from below to the top, when fertile, the obverse of each lobule are lined with orange coloured sori in two parallel lines. 

This species is perennial, but renews its leaves each year, as they dry out at the end of the spring.

Polypodium vulgare L.