Asplenium trichomanes, Aspleniaceae
This small fern you can see photographed growing on a variety of surfaces around Scotland, the maidenhair spleenwort, is fairly common in temperate and tropical areas of the world, but nonetheless probably my favourite one among the ferns I usually see growing around. I think the first few plants we learn to recognise and use as kids will always have a special place in our heart: when growing up while experimenting with plants in my grandparents’ garden I often played with this species when building terrariums and sometimes I would landscape bonsai pots with very small plantlets, to imitate the look of much larger ferns like bracken (Pteridium).
It is quite variable and several genetically different subspecies exist, which aren’t easy to tell apart by eye, but one empiric way is to observe where the fern is growing. Some prefer the alkaline conditions of lime mortar used in brick and stone walls, others grow on more acidic rocks, like the limestone commonly used here in central Scotland. It can also tolerate a variety of conditions and that’s why I tried to observe it in as many different situations as possible: in the photos above you can see it growing on very dry, sunny walls in coastal areas as well as on natural rocks in more shaded and humid locations up the hills, and all the in-betweens. If you want to try and collect some to establish it on a wall or rocky area of your garden, I can say experience taught me it doesn’t respond particularly well to being moved. Growing in tight crevices, it is very hard to uproot it without damage, unless the mortar is pretty old and loose or you can move the stones of a drywall. You might have better luck collecting fronds where the spore-releasing sori are visible and stuffing them between rocks and bricks, which you can then keep moist if very dry. With time the spores will do their part and you will end up with a highly decorative colony which needs no attention to keep thriving. It can look even better if grown together with the related, but larger and very different, hart’s-tongue fern (Asplenium scolopendrium), for contrast.