Is it Arabian Lilac? After seeing your post this morning I noticed it at the nursery. On theirs, in full sun, the leaf backs and stemps were quite purple.

I think you're right! Thanks. It looks like it doesn't need much water too. It was really quite a pretty shrub/small tree.

Rare in California until 2002 says San Marcos Growers. Good words get around.

Vitex trifolia 'Purpurea' is the botanical name.

Yes, it’s Vitex trifolia 'Purpurea' aka Arabian Lilac. They are related to the chaste tree. I have one established and I just put another in the ground, both in full blazing sun, zone 9b sunset 19. They do require steady water to establish in full sun, otherwise the leaves yellow and fall but now that my older one is bigger, it doesn’t require much. I’m limbing both of mine up into little trees to give the lower surrounding plants some shade. They are suppose to grow 6-10ft. The branches are kind of long, stick out, and then they droop, which I find kind of elegant. I have a lot of flowering plants and roses in my front garden, maybe too many, no place to rest the eyes. So I bought these solely for the pretty leaves. It’s does bloom little purple flowers, like a lilac, but I’m crazy about the leaves. Here’s my newly planted baby.