I don't know the ID of mine, but it grows 15 feet high each summer and lasts until about February (zone 7b). Then, it dies off, except new sprouts form at the base of the dead trunk and it repeats the action. We have started (this year) cutting it off like a buddleia since that seems to be what it likes.

Cameron

Here is a link that might be useful: My eucalyptus

I'm wondering the same thing as I just purchased a little 4-pack at a nursery. The plants are tiny right now and I know they are not hardy in my zone. I thought I'd use a container that won't be too big to bring indoors for the winter. When I lived in zone 7(PNW), I had one that behaved similarly to Cameron's, but wasn't quite that large.