5. Elderberries
Elderberries are safe when fully ripe and cooked, but their leaves, twigs, and seeds contain cyanogenic glycosides that can cause nausea, vomiting, diarrhea, and in large amounts, seizures or death. Proper preparation is essential to avoid illness. Despite their popularity in jams, wines, and teas, mishandling can make these seemingly harmless berries extremely dangerous.
