Two Trees and a Woodpecker

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 tree a son of a beech or a son of a birch?'

The birch says he cannot tell, but 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 and 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 poked my pecker into.

 

Thanks Ralph