Q. My husband found a plant growing wild in our garden with green berries in clusters that turn dark blue or black. He tasted a few and they seem to be okay. We looked at pictures on the Internet but it does not resemble any of the common berries. Did you know what this is? A. I think you have black nightshade. Several people have sent me pictures of this plant growing in their garden. It is a fairly common weed in the garden and landscape that gets mixed up with tomato and pepper seed. Black nightshade             This plant can be found worldwide and is extremely variable in leaf size, leaf color and whether the leaves are smooth or hairy on the surface. The berries of this plant are pretty consistent in size and color in a rather distinctive cluster and a good way to identify it. Fruit and flowers of nightshade             There are several countries that do eat different plant parts of nightshade and promote it as an herbal medicine, food or for livestock but the American black nightshade is poisonous and should not be eaten in any form.             Be careful of internet information. This plant, because of its variability, may vary in the amount of poison it contains in different parts of the world. To be on the safe side, consider it a poisonous weed and get rid of it.