I was walking on Anza Street near Arguello recently, and saw something I don't think I've ever seen in San Francisco - a mature orange tree. Actually bearing fruit. We have plenty of Meyer lemons, and orange trees aren't unusual in the warmer suburbs of the north and east bay and the Peninsula, but I don't ever remember seeing one in SF. And in the Richmond, no less - one of our chillier neighborhoods. It was in a yard over a fence, so I can't be 100% sure, but if you're curious, go to 916-918 Anza (very close to the Columbarium), and check out the tree over the fence!