It's an oak for sure don't know which species there are many.

Rose of sharon

Not an oak.

Perhaps a Hibiscus. Reminds me a bit of H. syriacus.

Flowers are described as small, 'thin' (not sure what that means) and unremarkable, so not RoS.

I viewed images of H.syriacus ( = R.o.S.), already ruled out
on basis of flowers.
Flowers aside, it was as though I were viewing my plant.

Enlarge the following:

As well as the flowers, the green barked branches and growth habit are different from Hibiscus syriacus. I can't enlarge your photo. What plant is it a picture of?

You probably did enlarge to read the notation, which is in the graphic.

Unnamed flower. I looked for anything that I could adapt to provide a
rough representation.

Any chance of it being Baccharis?

http://www.catnapin.com/WildFlowers/TreeShrub/tsWillowLIkeBaccharis.html

That was in the back of my mind but I just couldn't remember the name. I think you are right, Carol.

Carol nailed the genus. From there I found the species :

What a team we are. Truly grateful.

In book "Wild Flowers of Florida", I found an explanation
for the difference(s) between my tree and
photos /descriptions of B. halimfolia.
On individual trees, all flowers are either male or female.
Author wrote of male flowers that they are "much less noticeable".

Perhaps foliage density tends to follow suit.

I am prompted by that reading to correct the above-stated "Deciduous" to evergreen.
(Leaves did leave; now I recall that I pruned the branches.)