Hello Francesco,
To my eye, this is definitely not F. caperata. For one thing, the color is not right – although the pale yellow color produced by usnic acid that has given rise to the latin name for the genus (Flavoparmelia; flavus = yellow in latin), can be quite tricky to capture with a digital camera, I find. Did it appear disctinctly yellow in the field? Another, bigger issue, is the presence of punctiform pseudocypellae on the upper surface (the little white dots near the edge of the thallus). These point to the genus Punctelia, a hunch that can be confirmed by a spottest of the medulla (the white layer beneath the greenish upper cortex) with bleach (sodium hypochlorite = Cl). Species from the genus Punctelia react a reddish to pink color when tested this way. The reaction can be quite fleeting, so make sure to observe the reaction immidiately after applying the bleach.
I am not quite sure about the potential species of Punctelia in your area, but I would suggest looking into that genus for a good match.
Best regards,
Jonas
