at the bank of the little creek Mühlenerft near Frimmersdorf I ran across this one. It grew at the wayside between mosses:
Lobe cross section. Beneath the paraplektenchymatic upper cortex follows the layer with the symbiontic cyanobacteria (Nostoc). Under this layer we see a layer of loose ordered mycelium. All species of peltigera have no lower cortex.
Lobe cross section. A closer look at the paraplektenchymatic upper cortex. Phase contrast, 2 pictures stacked with Zerene Stacker.
Enjoy!