Stewart Robert Hinsley schreef
Taking a leaf off the tree and photographing it in isolation may assist
in identification. According to Stace the asymmetrical leaf bases of
Ulmus are unmistakable, but we don't have a clear view of the leaf
bases.

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I have no doubt at all about the asymetrical leaf base, which is pretty
clear. Also the lateral veins which run up to the leaf margin, which is
indeed doubly toothed. I am very inclined to Ulmus minor, but am put of by
all the small 'leafs' (stipules?) that are all over the place.
PvR