The primary toxin in Podophyllum species is podopyllotoxin found in greatest concentration in the plant at the time of flowering. The ripe fruit has little toxicity. Podophyllotoxins are readily absorbed through intact skin and the digestive tract. The toxicity of podophyllotoxin is attributed to its binding to receptor sites on tubulin, thereby blocking cell division and cellular protein synthesis in a similar manner to colchicine found in the autumn crocus. Podopyllotoxin has been extensively utilized in folk medicine is currently has value for its antiviral and anti-neoplastic properties
Only one species (Podophyllum peltatum) of some 7 species found in North America and Europe occurs in North America. As a common wildflower of eastern North America, it is often grown in wooded areas because of its spreading habit as a ground cover whose leaves emerge before the foliage of deciduous trees. Glossy green palmate leaves are produced on stems 18-24 inches tall, in pairs, with 5-7 lobes or partitions. Leaf veins are prominent and palmately arranged. A single creamy-white, 5-7 petalled, nodding, flower arising at the angle between the petioles is produced in early spring. The canopy of leaves often hide the blooms. The fruit is an oval berry containing many seeds that turns yellow when ripe.
Animals or humans eating the green "apples" are likely to experience severe diarrhea and abdominal pain. Excessive salivation and vomiting may be prominent.
Ingestion of large amounts of the May apple can lead to neurologic signs, liver degeneration, and bone marrow dysfunction. Poisoning in humans has occurred when Podophyllum products have been mistaken for mandrake (Mandragora officiinarum), an herbal medication with quite different effects.