18 trees with beautiful bark: Take a closer look
You missed my favorite...the Rainbow Eucalyptus Tree! I saw it on the Islands of Kauai and Maui. Gorgeous neon colors!
Madrona trees have a reddish, patchy/flaking bark that's very striking. I've seen them on the coast of Washington state and British Columbia: http://seattletimes.nwsource.com/html/outdoors/2002049584_nwwmadrona30.html