ID: Lecanora something?

[Hayseed]

ID please. Taken in Westgate, Co. Durham Churchyard. Seems like a Lecanora. Photo seems a bit squashed somehow!

[Hayseed]

I have a similar photo of a nearby lichen,but greener, like Frank Dobson's photo of L.Sulphurea. This photo is similar in colour to Mike Sutcliffe's L. Sulphurea. Any comments please?

[AlanS]

Hi Hayseed,

I have looked at your post several times, but it is difficult to give a definite answer. I am sure you are right that it is a Lecanora, but which one is less certain.

Each time I come back to the thought that it is an odd form of Lecanora rupicola.

This is a very variable species, often with a chalky white, much smoother thallus, but the thallus can be greyish and more warted, so that is not a problem.
What bothers me most is the way the apothecia are in dense clusters, which is certainly not typical, though I have seen hints of this in other photographs, and other species, notably L. polytropa, show similar variation.
Secondly, the young apothecia should be pruinose ("frosted") and that doesn't seem to be the case here.
The apothecia should also be more pink tinged (usually under the white-frosting), but there is some hint of the correct colour towards the top left of the photograph,
Lastly, there is no sign of Arthonia varians, another 'lichen' that is so common in Lecanora rupicola, taking over the apothecia, that it is almost a diagnostic character!

So all these features combine together to make me doubtful about it being L. rupicola, though I think it most likely is that species.

I mentioned L. polytropa, which is also very variable, but it usually has a discontinuous thallus, and is usually some shade of pale to ochre yellow or greenish. If your photograph shows the correct colour, then I don't think it can be that - but correct rendering of lichen colours by digital cameras, and indeed by flat-screen monitors, can be problematic.

On base-poor rocks, L. rupicola and L. sulphurea can grow together.

I don't quite follow your question about L. sulphurea, but it often comes out much too grey in digital photographs. Mike Sutcliffe's photograph is excellent, but other internet and published pictures (including in Dobson) may show the colour poorly.

AlanS