May apple. Flowers of the May apple (Podophyllum peltatum), a medicinal plant also known as the American mandrake or ground lemon. This plant has been used in herbal medicines for centuries for its beneficial action on the liver and digestive system. It increases the flow of bile and clears the intestines. It has been used as a treatment for intestinal parasites such as tapeworms. Overdoses produce nausea and vomiting, and some deaths have been attributed to this plant. In modern medicine, it is the source of the anticancer drugs etoposide and teniposide, which block cancer cell reproduction. May apple grows throughout North America.