Can you please confirm:
- This is Black-night-shade berries?
- This is an edible?
- Perennial or annual plant for Zone 9b (N.California)
- Best practice/time to propagate them (using the ripe berries)
Black nightshade - yes, Solanum nigrum see the wiki page here. Short lived perennial. Is it edible ... the wiki page has something to say on this; answers yes and no would be correct, but probably you are playing with fire. If it is just for yourself in a scientific context then be aware that the toxin is the same as that in greened potatoes after exposure to light. The plant resembles bittersweet (Solanum dulcamara) and can be confused with deadly nightshade (Atropa belladonna). If there are kids involved then they should be very carefully instructed and encouraged to pass on the message. In general no, don't eat, to be safe, and while it is easy to propagate from seeds it is an unsightly plant and best discouraged.