A buttonwood is a type of tree, most famously the American sycamore, that grows large and sturdy with distinctive peeling bark that reveals patches of white, tan, and greenish wood underneath. The name comes from the tree's round, button-like seed balls that hang from its branches through winter.

The buttonwood tree earned its place in American history on May 17, 1792, when twenty-four merchants and traders gathered under a buttonwood tree on Wall Street in New York City. They signed an agreement to trade stocks and bonds with each other according to agreed-upon rules. This meeting, known as the Buttonwood Agreement, created what eventually became the New York Stock Exchange, now the largest stock exchange in the world. That single tree witnessed the beginning of America's financial markets.

Today, people sometimes use “buttonwood” as shorthand for financial markets or Wall Street itself, honoring that historic tree. The original buttonwood is long gone, but the New York Stock Exchange still displays images of buttonwood trees as a symbol of its founding. These trees can live for hundreds of years and grow massive: some American sycamores reach over 100 feet tall, with trunks so wide that several kids holding hands couldn't encircle one.