4. Elderberries
We mostly relate elderberries as a medicinal plant and it has been often used as a medicine in homeopathy treatment. It is known to treat skin wounds, and cold. The leaves and twigs and the seeds of this berry are said to contain a chemical which is similar to that of cyanide. If you ingest these parts then you may have ingestion problems as well as nausea. If you do still want to consume it then make sure you use only the ripe berries or at least cook them thoroughly.