The family Passifloraceae is found world wide, excluding Europe and Antarctica. Nine species are found in the USA. Passion flowers from Ohio to Texas and south to the Florida Keys. The purple fruited Passiflora edulis and the yellow fruited Passiflora edulis var flavicarpa are widely grown in subtropical and tropical regions, respectively for their delicious fruits. These forms of Passiflora edulis have been found to be different species. They occur in different climate regions in nature and bloom at different times of the day. Passiflora edulis is self fertile and Passiflora edulis var. flaicarpa despite claims to the contrary, is self sterile. It requires two clones for pollinization.

"Passion" does not refer to love, but to the Passion of Christ on the cross. In the 15th and 16th centuries, Spanish Christian missionaries discovered this flower and adopted its unique physical structures as symbols of Crucifixion. For example: the 72 radial filaments (or corona) represent the Crown of Thorns. The ten petals and sepals represent the ten faithful apostles. The top 3 stigma represent the 3 nails and the lower 5 anthers represent the 5 wounds. The flower has been given names related to this symbolism throughout Europe since that time. In Spain, it is known as Espina de Cristo (Christ's Thorn). In Germany it was once known as Muttergottes-Schuzchen (Mother-of-God's Star).

In Japan, they are known as clock-faced flowers, and recently have become a symbol for homosexual youths. In North America they are also called the Maypop, the water lemon, and the wild apricot (after its fruit). Native Americans in the Tennessee area called it ocoee, and the Ocoee river and valley are named after it.