Passion flower

P. incarnata (maypop) leaves and roots have a long history of use among Native Americans in North America and were adapted by the European colonists. The fresh or dried leaves of maypop are used to make a tea that is used for insomnia, hysteria, and epilepsy, and is also valued for its analgesic properties. P. edulis (passion fruit) and a few other species are used in Central and South America for similar purposes. Once dried, the leaves can also be smoked.

The medical utility of only a few species of Passiflora has been scientifically studied. In initial study in 2001 for treatment of generalized anxiety disorder, maypop extract performed as well as oxazepam but with fewer short-term side effects. It was recommended to follow up with long-term studies to confirm these results.

A study performed on mice demonstrated that Passiflora alata has a genotoxic effect on cells, and suggested further research was recommended before this one species is considered safe for human consumption.