Actually, there is an elderberry that will grow in Zone 10 with no chill requirement.

When I lived in Florida, I bought a pair of elderberry bushes, neither of which grew well, and they both gave up the ghost. But not far from them, a bush grew that had been planted by the birds, and gave us large dependable crops every year.

I always thought it was the native American elderberry, Sambucus canadensis, but have recently found out that it may have actually been European black elderberry, Sambucus nigra, which takes warmer weather than the native variety will.

You may find that it will grow for you as well. I was in the Tampa Bay area, about ten minutes from the beach, and we had typically very hot and humid weather, even through much of the winter.

Elderberries are not trees, but large bushes, with a semi-vining habit. We have a few on our place, but we've never managed to get berries, because the deer strip them before we have a chance.