"Widest Tree in the World The Tule tree is estimated to be over 2,000 years old. It's not the oldest or the tallest, but at about 30 feet in diameter, it is the widest tree in the world, and it's quite impressive. The species is Taxodium mucronatum, but it's commonly known as a Montezuma Cypress. If you visit on the weekend, you can ask one of the local children who act as guides to give you a "tour" of the tree—they point out figures in the natural formations of the tree's bark and branches."