Etnobotanica brings together papers on European wild plant use in places that I would consider obscure (ohh that Dutch self-centredness). There is much on Albania and Macedonia for instance. It's a fantastic resource and I have pointed to another paper earlier.
"Wild food plant use in 21st century Europe: the disappearance of old traditions and the search for new cuisines involving wild edibles" by Łukasz Łuczaj and others gives a broad overview on the current status of foraging. It notes that one hand the traditional knowledge of wild food is disappearing while at the same time it is reinvented (not reintroduced as the paper argues) in avant-garde cooking.
In all it is a bit scattershot, but that is only to be expected for such a huge and complex field in which every country has its own history and where generally there little overlap between separate traditions exists. Good piece to get you talking. I am happy in the meanwhile with the different plant lists like this this stocking-list from a South Swedish wild food firm that also supplies Noma. It is a list that contains so many plants that are growing between the cracks of the pavements or in neglected gardens that it once again shows how much of Michelin-starred wild food cooking resembles the experiments of Surrealism to create extraordinary sensations by rearranging ordinary and/or discarded material like bus cards and cut-outs from newspapers.