A joke from P

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."