We have these cool trees at the Bear Creek Dog park that grow tennis balls. They are actually a bit larger than tennis balls but the same color. What better place to have a tennis ball tree than at a dog park? Mom looked it up on the internet and says they are reall called Osage Orange, but that is ridiculous, there is no orange color to them at all. People can be sooo stupid sometimes. Anyone with half a brain can see they are Tennis Ball Trees.