Hello. I would like to identify a suburban backyard tree presumably planted there by someone, but possibly a volunteer. It is growing moderately well in inland San Diego, zone 23 -- a bit yellow from thirst at the moment. It may be deciduous and dropping its leaves for winter, but it's currently 97F (so what does winter even mean here? ;-). No one remembers seeing flowers or fruit on the tree, but that could be a product of neglect.

The tree stands over 10 feet tall. The trunk is single, straight, approx 3.5" diameter at the base and 2" diameter at 5'. The bark is gray, crackled on the lower half, smoother on the top half. The leaves are oval, serrated, veined, approx 1.5" to 2" long and growing alternate.

It's difficult to take a photo of the tree shape, as the foliage blends right in with the neighbor's tree over the fence. The overall shape is generally round.

Any other details helpful for an ID? Many thanks for your help!