Tree id

I was sitting in my fathers garden this am and noticed a strange tree growing out of another was. When I investigated further I realised it was actually growing from the truck of a Kilmarnock? Willow. Any ideas what it is? I’ve attached 3 photos to help. Thanks
Lily

 

Can't see clearly, but kilmarnock willow is a grafted plant.

I'm assuming that the other tree which you are seeing is a sucker from the root stock.

 

Ah the other tree has completely different leaves, the long and spikey ones in the photo

 

I think Pete is spot on and you have an ordinary willow shooting from the rootstock onto which the Kilmarnock Willow is grafted. I would suggest you cut the branch below the black clip (middle picture) off as close to the trunk as possible and remove any further growth that appears from below the black clip.

 

Brilliant both, thanks very much