Polycaulonia or perhaps Xanthomendoza?

In LGBI3, Polycaulonia candelaria is described as having “lobes ± terete, not dorsiventral”, while P. ucrainica which is described as having “dorsiventral lobes” that are “upper side pale lemon- to green-yellow”.

We have found richly orange and decidedly dorsiventral examples in several sites in Warwickshire, and have been wondering whether they might be a Xanthomendoza species.  We thought maybe this one, from a nutrient-enriched sandstone headstone underneath conifers, was closest to either Xanthomendoza fulva or X. oregana, but are still very unsure. It really doesn’t seem to fit either of the Polycaulonia descriptions though.

Comparing photos to the scaled photos in “The genus Xanthomendoza in Norway”, Lindblom et al 2019, the scale seems closer to X. fulva. No pycnidia seen, so no conidia to measure unfortunately.