So I nipped outside the house and had a look on the house wall - limestone blocks with sandstone round the windows: west facing so pretty dry.
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You can see the little "jam tarts" about 1/2 mm across with a dark centre and white rim. In this example case they are indeed dispersed over quite a big area where lime rich water has drained onto the sandstone vertical "sill".
Usually I have seen them more clustered than that.
I found some on a ground level gravestone at Ingleton (see the end of that post)
Actually, now that I have been on a more advanced lichens course I wonder if I should check the identification by doing chemical tests and cutting sections of the reproductive bodies.. Maybe another day.
This is Lecanora dispersa at Inlgeton churchyard
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15. Caloplaca flavescens
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