Lichens on Stone Walls in Darwen, Lancashire

Over the last few months I’ve been paying attention to lichens. The trouble is, the more closely you look, the more questions arise.

After a while the boundary between stone and lichen seems to blur. Are some of these decorative patterns the stone itself, or are they all lichens?

Something rich is going on that we rarely pause to think about.

I found myself wondering why stone walls in some parts of Darwen have many lichens and others have none. Could the lichens have been imported together with the stones? But the wall looked old, and surely if our climate didn’t suit them, they would not be thriving.

Wikipedia taught me about the general types of lichens. There are ones that are shrubby, powdery, crusty, leafy (flat or with raised edges), and even some that look like hieroglyphics. It’s not clear cut as the types may overlap.

I wanted to know more and to be able to identify some of the more common lichens we have on Darwen’s dry stone walls.

After discovering that an internet search for ‘lichens with black spots’ brings up adverts for patio cleaners, I turned to the library and snapped up Lichens by Oliver Gilbert, my sole choice.

It all turns out to be a bit more complicated than I’d hoped. Being a lichen is a lifestyle choice some types of fungus may adopt, very roughly analogous to living in a commune with one or more partners.

We don’t have folk names for most lichens, and the terms used to describe them are not in common parlance.

Botanical names are based on the fungus, but a fungus that takes one form when it envelops partner A may also be able to partner with B, when it would take a different form. Even experts struggle to conclusively identify lichens without chemical tests.

To sort through the puzzle, Oliver Gilbert recommends carrying a lichenologist’s bag with a stout knife, observes that ‘some people are never seen with anything less than a 1.5kg club hammer’ and prudently suggests carrying a spare chisel ‘as they are easily mislaid’. It is normal to carry two or three reagents: potassium hydroxide solution and fresh bleach are essential; paraphenylenediamine is handy.

I can only hope lichenologists are not stopped and searched by the police.

A black and white picture in the book shows ten lichen fanciers, each with a canvas bag over their shoulder, observing with varying degrees of attention an old tree that does not appear to have any lichens on it.

I’m forced to conclude lichenology is not for me – the naming part at least. I’ll be calling them all Licheny Mclichenface.

But I will carry on admiring their subtle colours and patterns during local walks.

I learned some facts that will stay with me, for example, that lichens are some of the slowest growing things on earth, in extreme cases growing less than 3 mm (1/5 of an inch) in a century.

And that many patches of lichen we see are actually tiny gardens – a harmonious mixture of different lichens and mosses. Once I realised that, I seemed to see them with new eyes.

Some are more formal like miniature Japanese gardens, while others are free and easy combinations like cottage gardens.

Lichens remind me I’m really not cut out for a proper, scholarly approach to plants. For those of you who who are, here’s another thought. How weird is it that some lichens are formed from three different kingdoms of life (perhaps four), all in one life form?

For any regular readers who have made it this far, I’m ending with a confession. All the while I was out taking pictures, I was looking for a hidden Mickey. I haven’t found one yet but it’s only a matter of time.

Until then, I’ll leave you with a bear and a pig, in lichen form…

… and with a chance find that reminded me of the owl pellets Dad used to bring home to dissect for my sister and me when we were youngsters:

Shared for the Lens-Artists Challenge: Focusing On The Details.