Actually, I'm not much of a tree geek, Orville, but the list of British species reminded me of the loss. If you want to know more, Wikipedia, as always, is a good place to start:
http://en.wikipedia.org/wiki/Elm
Personally, I'm not to bothered about getting the precise tree species right, I think it is more important in a CG landscape to get
variation in fauna than worry about minor details.
I suspect Oleg may be tearing his hair out at the details we are nit-picking over, and possibly considering setting the next SoW in antartica - penguins have no internet access.