Lichen murorum
Illustration by James Sowerby for James Edward Smith's English Botany.
There are more details about the production of English Botany in the INTRODUCTION.
On the left are all the views of this species as shown in plate number 2157, published in about June 1810. The enlargement on the right shows the yellow-orange thallus, the darker orange apothecia and a cross-section. In the cross-section of the thallus you can see the green photobiont layer quite clearly. Below the photobiont layer is the white medulla (featureless in this illustration) and then the rougher, rocky substrate. In the text alongside the plate Smith included the comment that: "Nothing can be more common, nor more obvious, than this golden-coloured Lichen on calcareous rocks and stones, and the mortar of flint walls". In current taxonomy this lichen would be a species of Caloplaca.