This issue sponsored by
The Woodland League
A Short Note on Lichens and Rock Art
The origin and meaning of prehistoric rock art at times attracts theories either wild or unsupportable except with great faith in the unprovable. It is understandable, therefore, that when Ronan O'Flaherty wrote in Archaeology Ireland  of an apparent link between the growth-pattern of certain species of lichen and the typical pattern of cup-and-ring rock art, his observations were described in the most tentative language.
The discovery, on Valentia Island, initially appeared to be unrecorded cup-and-ring rock art, and worthy of note for that reason alone. However, on closer observation this 'rock art' turned out to be nothing more than a growth of lichen on the rock surface. To quote O'Flaherty, "curiosity . . . was quickly replaced by disappointment and just as quickly again by delight." The implications of the similarity between the lichen and the art it had initially appeared to be came to the fore. As noted in the text, features of a rock surface have apparently been allowed by rock artists to influence the form their art has taken on occasion. Though lichen grows on the rock rather than being a part of it, these long-living, slow-growing organisms could be fairly seen as a semi-permanent feature of the appearance of a rock surface.
O'Flaherty ends with the words:
"This is no more than a suggestion, of course, and hardly deserving of much more discussion. It is, however, with a certain malicious pleasure that I throw it into the pot . . ."
No more than a suggestion, indeed, but certainly one deserving of further discussion.
By coincidence, the very same topic had been discussed the previous month on the British Archaeology  and Stone Age Ireland  discussion groups, and has been the topic of some discussion over the last several years. Thus, it is not just deserving of further discussion, but is actually being actively discussed, albeit intermittently.
During the course of recent online discussions, several images - some quite striking - were made available, and a number of these have been included with this article. Amongst the stones discussed was one in the possession of this author. Found on the slopes of Lachtnafrankee Mountain in the Comeraghs, it is no more than a few centimetres across and had clearly split from a larger stone quite recently. On the fragment are several lichen growths of remarkable form (Image 1).
Lichen growth on a stone
from Comeragh Mountains, Co Waterford' © S.
Lichen growth on a stone from Comeragh Mountains, Co Waterford' © S. MacAmhalghaidh
Is this similarity between lichen and art a coincidence? Possibly. The circle is, after all, a very simple shape and one found again and again in nature, in human architecture and in artefact design and art. Two things make the association between lichen and rock art plausible, however: presence on stones, and scale.
Lichens have a great advantage over other sources of inspiration such as celestial bodies, ripples on water, and flowers simply because they exist in exactly the same sort of locations where cup-and-ring art is found. This is not to say that cup-and-ring designs are therefore mundane, meaningless imitations of natural forms simply because they do not reflect 'important' sights such as patterns of stars in the sky. We cannot know the significance of the art itself, and neither can we know what significance was placed on the forms that inspired that art. To look at lichens on a rock today, they may seem unimportant, trivial things. It is unfair, though, to reflect that modern perspective backwards in time.
Lichen growths also have the further advantage of matching quite well the typical scale of cup-and-ring art. So, too, it can be argued, do many flowers, rippling water and so on. It can even be said that, from a viewpoint on the face of the earth, the sun, moon and stars are visible on about the same scale. What perhaps clinches the issue, though, is a third point where lichens have an advantage over these other possibilities: permanence.
Flowers wilt and die in days, ripples are gone in seconds at best, and even the sun, moon and stars move constantly in the sky, travelling on a daily basis in and out of our vision. Lichens, growing on the same rocks that carry cup-and-ring art, and forming on a scale similar to that same art, are very slow-growing organisms. They remain little changed for years, and live considerably longer than a human lifetime. To all intents and purposes, they are permanent features of the rock surface on which they grow.
In a sense, the significance of cup-and-ring rock art is irrelevant here. Whether the symbols mark a sacred site, are way markers on a route, or boundary or property ownership markers, is a side issue. What is important to the present discussion is that they are permanent marks on stone. Why they were given the form they have - why those shapes, permanently marked on stone were significant - we cannot know. It does, however, seem plausible that the art may have been intended to replicate patterns of significance previously made by lichens that had now died. How might one preserve the symbols? Staining the stone is a possibility, but incising the lichen-patterns is a much more permanent solution. Of course, this is guesswork, but it serves to indicate yet again that there are reasons to treat the idea of lichen growth patterns as the inspiration for cup-and-ring art as a possibility with numerous points in its favour.
Lichen on a standing stone,
Bosiliack Entrance Grave, Cornwall © Keith
Lichen on a standing stone, Bosiliack Entrance Grave, Cornwall © Keith Davison
The strongest argument against the 'lichen theory' is that rock art, as a whole, does not comprise solely of cup-and-ring patterns but includes all manner of other designs such as lozenges, spirals, zig-zags and a variety of other complex shapes seen, for example, on some of the kerbstones at Knowth.
This is a fair point. Any theory, to be credible, ought to provide either an explanation for the whole corpus, or at least explain why only certain sections of that corpus are relevant. There are no lichen growths that can account for many of these motifs. Neither is there any well-formed argument why only certain motifs ought to be taken into account. The 'lichen theory' is, therefore, not sound as it stands at present.
. Nonetheless, it has several features in its favour, as noted above, and has the potential to account (tentatively, perhaps) for some at least of the more problematic rock art motifs. Several people have also commented, independently, on the similarity between the pattern created by lichen on the stone from the Comeraghs and the shapes carved on the right-hand side of Kerbstone 52 from Newgrange.
Rather than attempt to force the issue here, it is perhaps better to simply allow the images of lichens provided here to speak for themselves. This is, after all, not a formal argument of the case for lichen-inspired rock art, but merely an elaboration of the tentative comments made by Ronan O'Flaherty some months ago.
These ideas are also thrown with malicious pleasure into the pot. Call it intellectual cookery, perhaps. It will be most interesting to see if this soup of ideas is to the taste - or not - of the reader.
Lichen growing on a stone
from Glen Lethnot, Scotland' © George
Currie Lichen on a stone from
Comeragh Mountains, Co Waterford' © S.
Lichen growing on a stone from Glen Lethnot, Scotland'
© George Currie
Lichen on a stone from Comeragh Mountains, Co Waterford'
© S. MacAmhalghaidh
Stiofán MacAmhalghaidh is Project Mnager of the IRQUAS online Irish heritage project and Editor of INSIGHT Journal'
1. R. O'Flaherty, 'Hubble, bubble, toil and trouble Naturally occurring rock art on Valentia Island, Archaeology Ireland, Vol. 19 No. 4, 13