Rhubarb leaves
Rhubarb leaves contain high levels of oxalic acid, which is toxic to humans. Consuming even small amounts of rhubarb leaves can cause symptoms such as nausea, vomiting, and diarrhea, and in severe cases, it can lead to kidney failure and death. The stalks of the rhubarb plant are safe to eat when cooked, but the leaves should not be consumed. If you have a rhubarb plant in your garden, it’s important to keep children and pets away from the leaves and to dispose of them properly.