Whoa, I have no idea. We hit upon a market in that square, but didn't spend much time there. Is it like a bitter? We have a bottle of Fernet-Branca from an Italian friend that is like bitters. Just an idea.
Nocino is a sticky dark brown liqueur from the Emilia-Romagna region in Northern Italy. It is made from unripe green walnuts steeped in spirit... or so says Wikipedia. Sounds good, no??
My SIL picked up a bottle in Italy for us when she was travelling and working on the Ferrari North America team. The bottle was shaped, and painted brown like a walnut. Very tasty.