Two tall trees, a birch and a beech, are growing in
the woods. A small tree begins to grow between them,
and the beech says to the birch, "Is that a son of a
beech or a son of a birch?"

The birch says he cannot tell. Just then a woodpecker
lands on the sapling.

The birch says, "Woodpecker, you are a tree expert.
Can you tell if that is a son of a beech or a son of a
birch?"

The woodpecker takes a taste of the small tree. He
replies, "It is neither a son of a beech nor a son of
a birch. It is, however, the best piece of ash I have
ever put my pecker in.