Ghost gum

The tree on the right with the startlingly white bark is a ghost gum, one of the 700 varieties of eucalyptus in Australia.

Despite sporadic efforts with a field guide, I can reliably identify a maximum of eight or ten species of tree. One of those was eucalyptus, which grows all over the Bay Area where I grew up. Here just saying eucalyptus isn't much more helpful than saying tree. On the bright side, now I can identify three more species: the red river gum, the coolabah, and the ghost gum.