The government of California has asked for Australians to travel there to help them when their own eucalyptus forests went up (naturally, Australia was blamed because eucalypts aren't native there).
It's interesting and a lot of people probably don't notice it when passing through Los Angeles or San Francisco but if you travel in California away from the main cities the vegetation is very much like Australia. I was taken for a drive north and south of San Francisco some years ago and the sights AND smells of the vegetation was just like being back in South Australia.