A monkey ball tree is a native North American plant that produces green, wrinkled fruit that resemble unripe oranges covered in a mosaic of small, bumpy tiles. The plant is also known as Osage orange and can grow as either a tree or a shrub.
Osage oranges get their name from the Osage native people. They were the first to use the plant, fashioning its tough wood into bows, bludgeoning weapons and handles for tools. European settlers soon took on the plant as their own and used it as natural fencing for livestock. They planted the Osage orange because their livestock would not graze on it, though native animals such as squirrels readily eat the fruit.