Hi again Becky,
I have been away for a few days and I see that your
Caloplaca photographs have become more complicated.
Caloplaca is a difficult genus, with a number of new species recognised in recent years, and no wonder that the British Lichen Society is devoting a several day workshop to them next year!
However, I cannot agree with Alain's new suggestions.
He and I are agreed that your original '
verruculifera' is
C. thallincola, and he rightly points out that it is growing over
Verrucaria maura, as it often does. Fundamentally it is a species of the coastal splash zone, so usually relatively low on the shore. Of course, on Islay, the 'splash zone' is liable to be a lot more extensive.
So back to your '
Xanthoria parietina 2'. I said it is probably
C. flavescens, and that is still my best guess, but it does have rather long lobes to the lower right, indicating that it, too, could be
C. thallincola. Unfortunately you don't give any ecological information, and if your photograph was taken on rocks on the lower to mid-shore,
C. thallincola would become the more likely possibility. On coastal rocks it is often very difficult to distinguish between
C. flavescens and
C. thallincola on general morphology, and a microscope is needed. (I should also add that development of marginal lobes is very much influenced by the surface of the rocks - on rough rocks
C. thallincola does not develop its typical 'cartwheels' and some thalli may be completely without lobes.)
What it is
not is
C. scopularis. This is a minute species, generally less than 1 cm across, and unless your camera has staggering macro facilities with remarkable resolution, I don't believe your lichen could have been that small. It forms numerous, tiny, round, rather convex colonies with very crowded apothecia, on exposed, sunny rocks where it gets a lot of 'downfall' from seabirds, so it is exacting in its requirements - a rare species in Britain, and pretty much confined to headlands with adjacent bird breeding colonies. There is a record from Islay, predictably from the Oa, but the chances of your casually coming across it are pretty small. Bluntly, your photograph is very little like it and I find the suggestion surprising.
I remain reasonably happy that your
Caloplaca crenularia is correctly named. It is very wet and looking strange, as many do when wet, but towards the top of the photograph we can see less water-soaked apothecia that look typical of
C. crenularia, and which are set on a granular grey thallus, quite different from the smoother, 'felt'-textured, yellow thallus of
C. ochracea - which in any case is a species of hard limestone, rare in western Scotland.
C. arenaria can look very similar, and grows side by side with
C. arenaria on the Ayrshire coast, but unless your site was a volcanic dyke, I would stick with
C. crenularia as the most probable ID.
.....................................
So on to your fencepost lichens. These are not my favourite lichens - I have a lot of packets awaiting examination/chemical testing and photographs, notably of
Lecanora, awaiting the results of such examination, but I'll make some suggestions.
Firstly the foliose species - looks distorted but seems to be
Parmelia sulcata.
Below this we have a
Lecanora with convex apothecia that are crowded together and consequently angular, margins becoming turned under with maturity. This is
Lecanora symmicta.
Upper left we see a more yellowish
Lecanora, with flatter apothecia and margins that are visible but seemingly irregular (from being sorediate). This is
Lecanora confusa. Ideally it would be tested with sodium hypochlorite (bleach) - orange reaction separates it from the very similar L. varia, but the latter is rare in western Scotland (though I have seen them side by side on worked wood on the Ayrshire coast - rather proud of myself that I already correctly recognised both before the bleach test
). There are additional, scattered apothecia of
L. confusa around the
L. symmicta.
Moving to the right there is a large
Lecanora thallus with red-brown apothecia with conspicuous white margins. This is either
L. saligna or
L. pulicaris, which both vary in colour and need chemical tests for ready distinction (and there are also some additional, newly recognised species in the
L. saligna group). I favour
L. pulicaris, but it is best not named from a photograph.
Further to the right is the thing with black, very convex apothecia, seemingly a
Micarea. My best guess is
Micarea denigrata, but there are other species (including
M. lignaria). Microscope work and chemical testing of apothecial sections needed.
Finally, there are the large patches of yellow soredia. I wonder what they are? My first (& only) thought was
Mycoblastus fucatus, but the soredia are typically more green or green-blue.
Alan
They're all within a two minute walk of my house. The rocky shore ones I have a key for but not the fence post ones 'cos I think my dad's gone away with my key! Can't wait for the new Dobson book to come out so I can get a copy. Thanks in advance for any ID help. I really appreciate it!
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