Two trees are growing in a forest.

Deep in the forest are two trees growing together. A beech, and a birch.

One day, a small tree begins to grow between them. The birch says to the beech, "Do you think that's a son of a birch or a son of a beech?"

The beech says "I don't know if that's a son of a birch or a son of a beech."

Just then a woodpecker landed on the small sapling. The birch asked the woodpecker, "Woodpecker, you're a tree expert. Is that tree you're on a son of a birch or a son of a beech?"

The woodpecker pecked the sapling a few times then looked up at the birch and the beech. "This sapling is neither a son of a birch or a son of a beech. It is, however, the best piece of ash I've stuck my pecker into before."

Edit: Wow trees are not a thing. Two trees are.