Just got back from a week in the Azores - Sao Miguel and Terceira islands. The Azores are Portuguese islands in the middle of the Atlantic Ocean - 800 miles west of Portugal, and about 2000 miles east of Boston - volcanic islands, with a mild, San Francisco-like climate (coastal, rarely above 80 degrees fahrenheit, and rarely below 45 degrees).
It was interesting to see so many introduced trees in the Azores that are popular as ornamentals here in San Francisco. Metrosideros excelsa (New Zealand Christmas tree) is often used as an ornamental, but also naturalized in the forests of hte islands (which I have never seen here in California). The New Zealand Christmas tree in the photo above was a huge specimen in Ponta Delgada, the capital city of the Azores - so big that it had supports to hold up its limbs - if you look carefully you'll see the many vertical steel supports. Araucarias are everywhere as specimen trees -- especially Norfolk Island Pine trees. (The Norfolk Island Pine in the photo below was a young specimen just outside our hotel window in Angra de Heroismo, the largest city on Terceira Island- the hotel was in an early 1600s stone fort built by the Spanish during a 40 year period when they controlled the islands). And Pittosporum undulatum (Victorian box) is everywhere as a naturalized tree - to the point where there were forests of the tree - it has become an ecological problem on the islands.
There are trees that are native to the Azores - in fact endemic to them (found in nature only there). It was interesting to see native species that were closely related to trees I recognized, but which had developed into separate species as a result of the physical isolation of the islands. Laurus azorica, for example, was obviously a close relative of the Grecian bay (Laurus nobilis) that is found on our streets.
And London planes (Platanus X acerifolia) lining the roads everywhere. The trees below were in a back road on Terceira island.