This plant may be native. There are several varieties of purple Nightshade on CalFLora that are native; several, non-native. I am not an expert.
According to CalFlora & Califorinia Poison Control System, ALL species of Nightshade or Solanum are considered Class 1: MAJOR TOXICITY, causing serious illness or death.
Disclaimer: The Corralitas Red Car Property Blog prefers to quote reliable sources, such as CalFlora and California Poison Control on the issue of toxicity. We often get email suggesting some plants are edible. If you are eating your way through the Red Car Property, we DO NOT recommend you eat any plant you find in the Red Car Property neighborhood without first doing your own research.