AL near FL border, volunteer in mostly shade. TIA! I can try to get a pic looking into a bloom if it would help. (When it stops raining.)

I see a flower that is only partially opened. While we wait for more pictures I'll throw out three guesses:
Solanum nigrum
Solanum ptycanthum
Solanum americanum/American Nightshade/Glossy Nightshade - This is the one my neighbors grow as an edible; I grow it but do not eat it myself.

TYVM! I'd looked at the first & last, but the middle one has quite a few pics "out there" with much smaller blooms, from what one can tell about scale from pics w/o objects or other plants, so was comparing to the berries mostly. The one bloom looked open, when I took the above pic, but was so small, attempts to get a good photo were a total fail. I was hoping the size of the bloom might be a good clue to ID.

Is there a time of day that's best to observe Solanum blooms?

For photographing the flowers, daylight hours is all I can suggest. Each time I have tried to photograph my Solanum all I get is blurry images. Most of my attempts end up in the dump file.

Here is a link from the University of Massachusetts with plenty of photos to help with identification. To my eyes the leaves on yours would indicate your plant is not S. ptycanthum judging by the leaf margin.
https://extension.umass.edu/la...

This link describes the different types of Solanum - look at the one called Hairy Nightshade; the link says the flowers are small. http://ucanr.edu/sites/Weed_Ma...

The two links should give you an idea of which parts of your plant need images to help with the identification.

TYVM! Will attempt more pics when it's not raining (or dark!)

...or dark.
I just went out to check on my plants but they are finished for the season so not help there.