Let us travel back through time and space until we reach Rome in 1609. At this time a monastic scholar by the name of Jacomo Bosio was working on a treaty about the Cross of Calvary when an Augustan friar named Emmanuel de Villegas, coming back from Mexico showed Bosio drawings of a "stupendously marvelous" flower growing in the New World. Bosio studied the drawings and was stunned in recognizing the various tools of the Passion: the corona (threads inside the flower) representing of course the crown of thorns, the three stigmas were the three nails, the tendrils matched the cords which attached the Lord, the five petals and five sepals were the ten apostles, Peter and Judas being absent. He also observed that the flowers took time to build and then remained open for just one day, concluding that God would allow only the most attentive and worthy ones to see such marvels. This is where the plant took its name and the fruit coming from it obviously had to be Passion fruit. Those various symbols have been further used by Spanish missionaries to explain the mysteries of the Passion to the people of Latin America, adding a few symbols on the way like five lobed leaves soon becoming the hands of the mourners and the nectar drops sometimes present would be blood from the holly wounds.
Now, from a less passionate point of view let us get a closer look to those wonderful plants. The genus Passiflora belongs to the Passifloraceae family together with 17 other genuses of much less known plants. The genus Passiflora itself is subdivided in 24 sub-genuses with a total of 465 recorded species. 95% of those species originate in America, mostly Central and South, with two species from North America, P. incarnata (May Pops or May Apple) being the best known. A few species occur in Australia and South-Eastern Asia, none in Africa or Europe. Regarding Africa, though the genus Passiflora is absent, other lesser known genus of the family are present such as Adenia, Dilkea, Ancistrothyrsus, Adenia being probably the best known by caudiciform enthusiasts. Amongst those many species some twenty produce edible fruits though only three are commercially grown on large scale, Passiflora edulis (purple passion fruit or purple granadilla), P.edulis flavicarpa (yellow passion fruit) and P.ligularis (sweet granadilla). More and more are nowadays sold in garden-centers and nurseries for ornamental uses as they display wonderfully coloured flowers, some being also perfumed. Hybridization is quite easy to perform and has given raise to many ornamental hybrids with the added interest of using hardy species (such as P.incarnata) crossed with colourful tropical species to produce spectacular plants able to withstand non-tropical weather.
Passionflowers can be grown outside in suitable climates, requiring well drained soils, sandy ones being perfect as the roots will not live long in compact and soggy soils. They can also grow indoor provided they get enough light and atmospheric humidity, air dryness being quite bad for any tropical plants. You can easily use seeds from passion fruits bought in local stores though result is not guaranteed if they come from hybrids or selected plants which are to be propagated by cuttings or grafting.