What is the meaning that Cardinal Federico wanted to give to this copper palm tree, located in the heart of the Ambrosiana Library? The palm, by its nature, has a polymorphic, very varied, symbolism. The first reference is to the Holy Scripture; in the Psalms we read that “the righteous will flourish as a palm tree” and therefore the palm, as a religious symbol, refers to loyalty. But we also have other symbolisms, which come both from the pagan and the generically human culture; let’s think, for example, of the palm tree as a symbol of regeneration. The palm tree, when it seems that it is drying out, suddenly flourishes again, it turns green again, as if to indicate the regeneration of nature. The palm tree yields the dates which are a food and therefore it is also a source of sustenance; from its leaves it is also possible to obtain, as a papyrus, some sheets on which to elaborate cultural instruments. They are all particular elements that we find documented in the typical literature of the Ambrosiana Library, where we tried to probe this symbolism that I have precisely defined polymorphic.