Always seem to struggle with foliose lichen so the best way to get good at them is to keep trying. First clues were with UV and chemical tests. There was a faint UV+ purple, C- and K+ yellow turning red. Visually the upper surface showed many fine cracks showing the white medulla and the underside was mainly black with brown lobe tips. The rhizines present are simple and fading towards the lobe margins but the lobe tips had some sparse simple rhizines. Overall this was enough information to key out this foliose lichen to Parmotrema reticulatum.
Found this morning on a wooden gate. Only a single simple spore was found with 1µm epispore measuring 10x7.5µm not enough to to be certain of identity. If this was a typical spore then Lecidella elaeochroma f soralifera a contender but tests show it to be something else. The thallus was UV+ white and C- suggesting something more like perhaps Fuscidea lightfootii. However, when performing a second section on a younger looking apothecia I found multiple dumbel shaped spores which were typical of Fuscidea lightfootii measuring 8x3.5µm