r/whattreeisthis

I would love to know what these little trees are. Can anyone identify them for me?

Moved in to a house that had been left sitting for a few years and this tree suffered the worst of it. It had largely grown into a bush with overlapping branches choking itself out. We trimmed it but we plan to cut it down when finances allow and put something new there. But I’m wondering what kind of tree it is in case I should save the logs for mushroom growing or some other purpose.
It drops lots of little black seeds (open in one picture) and blooms with tens of thousands of little white flowers (I will miss those).
Southern California Zone 10a