After city authorities felled an historic tree in Piazza Castelnuovo on Via Liberta` to make way for a new subway line, these guerilla gardeners went into action. They researched and wrote up the life story of every tree on Via Liberta`, including its present state of health, and with a knotted string attached each bio to each tree. They did this to sensitize the people of Palermo to the greenery around them. Some people in Palermo love their city.