Solanum ptycanthum Dun. Eastern black nightshade is only found in North America east of the Rocky Mountains.
Black nightshade is found worldwide, and is the prevalent nightshade in California.
These species are in a different genus from the uncommon but widely known deadly nightshade. In fact, both eastern black and black nightshade are sometimes used as food plants. Consumption should be approached with caution, as alkaloid levels may be at dangerous levels in some biotypes of either species. The nightshades are resistant to trifluralin, which helps explain their rise in importance as more and more crops rely on trifluralin for weed control. The nightshades can be very competitive, and can survive under a crop canopy, to rapidly increase in size as the canopy opens up or dies back.