Tan Ear fungus, Otidea alutacea, a ground-living member of the Pezizaceae (Ascomycetes). Unlike Peziza which forms a soft cup, Otidea has a vertical slit, making it more like an ear really. On soil below the big Oak tree behind the main pond in Gunnersbury Triangle.
Update: Glad to see there’s been quite a bit of interest in this page. Good news for you, then: on the 2021 Fungus Foray (photo), we all saw quite a few Tan Ears dotted about the western side of the reserve.
The English seem unemotional … except for their passion for nature
