Species of passion vines (Passiflora spp.; family Passifloraceae) that twine upward in tropical, subtropical, and some temperate regions of the world. They occur most often in wet forests, though some species may occur in drier, more open places. These vines have glossy leaves shaped like rounded human hands, and their flowers are often sweetly scented and packed with a ring of colorful filaments. The tendrils of passion vines hold the flexible, immature parts of the plants in place as they grow over and across other plants and physical obstacles.
The genus Passiflora, the best known group in the family Passifloraceae, also includes genera such as Adenia and Basananthe, both principally known from Africa. The plant families related most closely to the Passifloraceae are the Turneraceae, (watermelons, cucumbers), and Begoniaceae (begonias).
Humans have long valued passion flowers for their beauty, cultivating them in greenhouses and gardens, and as annual plants in temperate zone gardens. Most species are not hardy and need extra protection in temperate regions, with a notable exception being Passiflora incarnate, the maypop. This vine occurs naturally in the southern and middle states along the Atlantic coast of the United States. Its egg-shaped fruits follow fertilization of the white or purple flowers, and were once eaten by Native Americans and used medicinally as a sedative and anti-inflammatory.
The passion fruit flavor in prepared foods usually comes from the fruit of Passiflora edulis. Other notable fruits produced by species of Passiflora include the football-sized granadilla, from P. quadrangularis. Popular ornamental species include P. caerula, with its sky-blue flowers; P. alato-caerula, a blue-purple flowered hybrid; and P. mollissima, the banana passion flower, so named for the shape of its fruit.
The passion flower was used by Catholic missionaries in the Americas to teach about the crucifixion of Christ. It is the events of Christ's "passion," or suffering, which were said to be represented in the parts of the flower: three stigmas or female receptive parts for the three nails used in the crucifixion, the five anthers for Christ's five wounds, the spiky corona for the crown of thorns, and the five petals and five sepals for the ten faithful apostles (the twelve apostles minus Peter and Judas). Additional interpretations are sometimes given to other parts of the plant, such as the identification of the rounded leaves with the hands of those who crucified Christ.