Passion flower is one of 500 or so species that make up the Passifloraceae family of flowering plants and vines, many of which produce exceptionally showy blooms with an abundance of nectar that attract insects and birds.
P. incarnata is one of the hardiest species of passion flower and is commonly found thriving in wayside pastures, thickets and along river banks of the southeastern United States. In fact, passion flower is the state flower of Tennessee.
The aerial parts of the plant—leaves, flowers and stems—are widely used in herbal tea blends. Passion flower has a particular reputation for inducing a state of calm and relaxation. It's also quite tasty, on its own or mixed with other herbs, flowers or fruit peels.