Re: Pedant alert
I wondered who would ask this...
Oldest tree: Llangernyw Yew, Wales
http://en.wikipedia.org/wiki/Llangernyw_Yew
The Fortingall Yew, Scotland, may be a possibility for this too
Tallest tree: Reelig Glen, Scotland
http://www.scotsman.com/news/odd/tallest-tree-in-britain-found-in-highland-glen-1-3353599