I have no idea what species of tree this is. We came across it at Greys Court, a NT house in Oxfordshire. From a distance it looked unreal, possibly painted plastic with some of the paint having run in a rain shower to reveal yellow undercoat. Even quite close to, it was hard to believe it was real, though eventually the bark gave the game away.
If anyone knows the species (I suspect an Asian origin), please leave a comment.