The maidenhair spleenwort is easily the most abundant of the five species, probably making up about 90% of the ferns found on the wall. Having looked at the other side of the wall and corresponding walls in other gardens, it seems that the species seems to prefer a north facing aspect.

After the Maidenhair spleenwort, this is the next most common of the five species found. It seems to prefer the top of the wall, rather than the mortar on the vertical surfaces and is found on the higher section of wall, sheltered between the two houses, rather than the length running along the pathway.

By far the smallest of all of the ferns found. At first glance it looks like a flowering plant, but when you turn to the underside of the leaf, sori (which contain the sporangia) are visible. In the photograph these can be seen on two of the lower leaves on the right hand side.

Sporangia are the means whereby ferns reproduce and sori are often a vital diagnostic feature in successfully identifying ferns.

The Hart's tongue fern is probably one of the easiest to identify. There only appears to be the one plant of this type on the wall. Its long sori are arranged in two rows, one either side of the main stem or rachis. It was thought that this arrangement somehow looked like the feet of centipedes and hence gave rise to its name, scolopendrium from the Latin for centipede, Scolopendra.

Again only a single specimen. Identification was difficult as there were no sori present. However a bit of detective work helped me make a guess when I noticed a large, well established male fern in the border just below the wall. I suspect that an entrepreneurial spore has managed to get a hold in a gap in the mortar.