3. Rhubarb leaves
Rhubarb root is poisonous when raw. The leaves are incredibly dangerous no matter what.
Rhubarb leaves contain a toxin called oxalic acid which can cause serious kidney damage or even death. Symptoms of the poisoning include difficulty breathing, burning in your mouth or throat, nausea, vomiting, eye pain, stomach pain, and red urine. A small amount can make you very ill and eating ten pounds will almost certainly kill you.
Next: Skip these on your salad.