Passionflowers are members of the Passiflora genus, which consists of over 500 flowering vines and shrubs. According to legend, a Jesuit priest who struck a passionflower plant in South America believed that the physical structure of the flower head was symbolic of the Passion of Christ, a term that collectively refers to the incidents that led to the crucifixion of Jesus. Just as there is great diversity in species within the genus, a vast assortment of colors exist among passionflowers as well.
Blue and Purple Passiflora
Blue crown passionflower (Passiflora caerulea) typically sports 3-inch mint-scented white flowers crowned by white, blue and purple filaments. Since this species is one of the few passiflora which may tolerate indoor settings, it’s a popular choice as a houseplant. Outdoors, P. caerulea performs best at U.S. Department of Agriculture zones 6 through 10, sometimes even producing an egg-shaped, lemon juice. As stated by the Royal Horticultural Society of the United Kingdom, however, it should not be eaten because of the risk of stomach upset. The edible fruit commonly called passionfruit is harvested from P. edulis. P. incarnata, also referred to as purple passion vine and apricot vine, creates vibrant purple blossoms. Since this species is heat and cold resistant, it has a broad native supply throughout the U.S. and continues to be released to USDA zones 7 through 10.
Red Passiflora
Passiflora vitifolia, commonly called crimson passionflower and grape-leaved passion fruit, is native to Peru, Venezuela and Nicaragua. This species, hardy to USDA zones 10 and 11, features crimson red flowers and is noted as a prolific bloomer, even in colour. Another species which boasts crimson flowers is P. racemosa, sometimes referred to as red fire vine or red passionflower. This Brazil species is hardy to USDA zones 10 through 12 and is acceptable for container gardening and use as houseplant as long as there is enough humidity.
Yellow Passiflora
Passiflora foetida is just a species of passionflower that’s also known by many different common names, like Corona de Cristo, fetid passionflower, scarlet fruit passionflower and running soda. The showy blossoms of the plant, which can be often yellow but might also appear as green as well as purple, open from the morning and close at night. P. foetida is acceptable for containers and hardy outdoors in USDA zones 9 through 11. Another species which creates greenish-yellow blossoms is P. suberosa, popularly called devil’s pumpkin, indigo berry and corkystem passionflower. This species is a low-growing vine with smaller flower heads, hardy to USDA zone 8.
White Passiflora
Passiflora incarnata “Alba” is a fast-growing vine that produces large white blooms between July and September. Hardy in USDA zones 5 through 9, this species prefers low-moisture woodland environments and can even endure sandy soil. Although it’s herbaceous, or dies back in cold winter temperatures, its possibility of returning for another season improves with protection from severe cold and wind.