Here are some examples of how "tree" could be used as part of a proper noun:
* The Great Tree: This could be the name of a specific, famous tree.
* Oakhaven: A place name incorporating the type of tree.
* The Redwood National Park: This place is known for its specific type of tree.
To give you a proper noun for a tree, I need more context. What kind of tree are you thinking about? Is it a specific tree, a type of tree, or a place related to trees?
