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The leaf shape and general size and structure of the flower spike do not fit with Stachys palustris. I am sure there are many other possibilities in Italy.
You are right, it is not Stachys. Thanks.
It actually rather have the general looks of a Galeopsis...
Love all your pictures from Italy by the way!
Galeopsis seems worth checking out.
using this resource
Lat/Lng: 45.83422, 13.5522