The Treasure Tree Adam is an example of the numerous legendary elements of the One Piece world. It features exceptionally high-quality wood, as well as a mysterious genesis. According to the shipwright of the Straw Hat Pirates, Franky himself, this legendary tree was at least mentioned in building the second ship of the crew, the Thousand Sunny. In fact, Franky explains that the Tree Adam, the Treasure Tree, is located on an island far from Water 7 that has been consumed by war, where he had gotten the wood to build the Thousand Sunny.
The wood of the treasure tree, Adam, is pride of place due to its strength and durability for making a ship. Its superior quality makes it very rare, almost like a "treasure" in the world of One Piece. The Thousand Sunny really proves itself to be quite strong in situations all through the series because it's made from Adam wood.
In the world of One-piece, Treasure Tree Adam is always mentioned alongside a different legend of a tree, Sunlight Tree Eve. The first thing one may think of immediately here is the depiction of these two Trees into a pair or a coupling, in specific connections to the biblical Adam and Eve. Mention of these two trees by Eiichiro Oda has had a lot to do with bringing about a number of theories alongside their position within the grander scheme of things of the story.
Some theories say that the Treasure Tree Adam could be placed on Elbaf, an island considered to be one of the most important places within one piece lore. Elbaf, or the kingdom of giants, has been referred to by many people throughout the series but still remains unexplored. All monotonous facts about the Treasure Tree Adam suggesting its possible location on the fabled Elbaf island may hint at a next-door future story arc that will focus on such an island and its relation to the tree.
The importance of the Treasure Tree Adam lies not only in its practical use during shipbuilding, but also its use in some other speculated significance in the mysteries related to the world of One Piece. The point is, it could have importance far beyond basic application in building ships. Some fans even speculate something to that overall mystery of the One Piece world. One of the theories says that Adam and Eve trees could relate to the creation of Devil Fruits—mysterious fruits holding the power to give its user superhuman abilities. Although this is not confirmed within the official story, it gives a dimension to the quality of speculation and intrigue surrounding such legendary trees.
Another theory brings the Treasure Tree Adam and the Sunlight Tree Eve in relation to the Ancient Weapons: very powerful entities or very important objects in the world of One Piece. It speculates that the power of the trees might have gone into the form of the Ancient Weapons, like Poseidon and Pluton, but this is purely speculative.
The Treasure Tree Adam is not the only instance of an important tree in One Piece. Another example would be the Tree of Knowledge on Ohara Island, which was destroyed in the Ohara Incident, an event comprising the central element of the series' backdrop; it had stored a huge library of historical texts. The very name and the meaning of the Tree of Knowledge evoke powerful associations with the biblical tree of the knowledge of good and evil, thus strongly hinting at the mythological subtexts running through the world Oda constructs.
This is further reflected in the importance of the Treasure Tree, emphasized by its rarity and how elusive it is in terms of acquiring the wood itself. Franky being able to get a hold of Adam wood to construct the Thousand Sunny, in and of itself, is portrayed as being a remarkable feat, which further serves to emphasize the worth of the material itself and how very elusive that is. The element of rarity works to greatly add to the mystery that is associated with this tree and the functions it is likely to play in future interventions.