The metaphor here is more than linguistic resemblance; it is an element that transcends language restrictions and elevates the rood to the level of poetic figure. The poem's metaphor is the cross itself, because the cross pushes viewers to perceive a new universe. In modern terms, we could say that the cross functions as a visual metaphor. The root is the part of the tree that connects it to the ground. It also serves as support for the rest of the tree. Without roots, the tree will soon be destroyed by wind or water. In English, we often use the word "root" as a metaphor for their source or foundation. For example, someone who steals other people's ideas has no original thought of their own, they're just taking things from others and putting them together in a different order. Or, someone who causes problems for others simply because they can get away with it is looking out for number one over everyone else. They are showing no respect for others, which is why we say they have no moral compass or they're doing what's wrong. At its most basic level, then, the root represents your origin or where you come from. It is everything about you that is unique and individual. Without your root, there would be no you to speak of. You would be a copy of some other person, perhaps even including some of those traits you find unpleasant.