Two trees

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."