Hi.
For several years I have met this species growing in me only in one place. It is an old deciduous forest with a small admixture of conifers. Quercus, Caprinus, Acer are found nearby.
This species has already been repeatedly presented in various forums, but no name was found anywhere. Usually referred to as P. cf. howsei and I also describe it in this way, although it does not completely match the modern concept of this species described in "Morphological and molecular study of Peziza emileia
and P. howsei, two distinct taxa "- G. Merardi (2014).
Hohmeyer's key leads to this species and gives no other choice, although the size of the sporocarps and spores does not match it :(
In extreme cases, my sporocarps reach almost 10 cm in diameter. Here I present photos from the current year.
More photos and information about it can be found on my website; https://grzyby-pk.pl/gat-p/peziza-howsei.php
There is also a collection from another place, about 20 km away from it (presented on my page at the bottom of the page). The spores of this second collection, however, are definitely longer and a large part of them have a more dense ornamentation at the spore poles. Both collections do not have a layer composed of an intricata texture under the subhymenium.
Any suggestions are welcome.
If anyone were interested, of course, I have fruit bodies (dried, even from this year).

I first met her in the same place in 2014. She was almost completely white. As I noticed, its color depends on the age of the fruiting bodies and atmospheric conditions prevailing in a given year. I presented them at the Bio-Forum:
https://www.bio-forum.pl/messages/33/677649.html
best regards
Mirek