Passiflora, known also as the passion flowers or passion vines, is a genus of about 500 species of flowering plants, the namesakes of the family Passifloraceae. They are mostly vines, with some being shrubs, and a few species being herbaceous. Several species of Passiflora are cultivated outside their natural range for their beautiful flowers and delicious edible fruit. The leaves and roots of some, if not all, members of this genus contain a substance called passiflorina which has similarities to morphine and is said to be an effective tranquilizer. Many species are used in herbal infusions to calm the nerves and help bring about a restful sleep. The leaves of many species are also considered to be anthelmintic, anti-hysteric and diaphoretic. They are used in Brazil medicinally to combat intermittent fevers, cutaneous inflammations, and erysipelas. Hundreds of hybrids have been named; hybridizing is currently being done extensively for flowers, foliage and fruit. Most species have round or elongated edible fruit from 5cm to 20cm long and 2.5cm to 5cm across, depending upon the species or cultivar. Passiflora will adjust to any kind of soil, except desert conditions or very alkaline soil. Prefers full sun but will do with a light place or even half-shade. Passiflora need abundant watering during the growing season. In winter watering can significantly be reduced but good soil moisture must be maintained.

Passiflora quadrangularis, also named Passiflora macrocarpa or Giant Granadilla, is a perennial vine, looking much like Passiflora alata, but its flowers are bigger. Native to Central and South America it is grown for its large ornamental fragrant flowers and the large fruits. It climbs by means of clinging tendrils and can be kept as a container plant. The long tendrils need lots of support for climbing. It may be grown as a houseplant in a sunny window. One of the loveliest and most exotic of the Passion flowers producing gorgeous purple, white and blue banded fragrant flowers, measuring 8 to 10 cm across in a long succession from mid-summer to autumn. It produces giant green to yellow Passion fruits reaching over one foot in diameter. The pulp is white or greyish and is not as flavourful as the common Passion fruit, but still tasty and often eaten or used in drinks. Pruning is a must to keep the vine healthy. Prune off less vigorous growth and occasionally prune back vigorous growth to promote flowering. Protect from frost or plant in frost free areas. The Giant Granadilla is hardy to 1°C when mature, frost tender when young. Provide ideally a temperature of 15°C to 28°C. Keep the atmosphere humid through the summer and place in full sun, can tolerate partial shade. You may need to water your plants daily during the hottest summer months. During the winter the roots should be kept moist, but as growth will be much slower you will probably only need to water once a week, depending on growing temperature. It will do best in a loam-based mix with a little peat moss. If their pot is too large or if they have an unrestricted root run, then the whole plant will simply get bigger and bigger, but it will refuse to flower and therefore fail to produce the fruits. By limiting the pot size, you are limiting the ability to grow and this is seen as a threat, so the natural mechanism is to produce seed for the next generation. A suitably sized pot for an adult plant would generally be of 30cm in diameter.