Passiflora, known also as the passion flowers or passion vines, is a genus of about 500 species of flowering plants, the type genus of the family Passifloraceae.
Exotic looking Passion Flowers look as though they'd be tropical plants, but they can actually be grown in much milder areas. There are many different passion flower species, with considerable variety within them. Some passion flowers are vines, some bushy, some even produce edible fruits.
Passion flowers look extremely delicate, so it’s a surprise to find them growing in fields along the sides of the road.
The common name Passion Flower can be a bit confusing. To muddle matters further, most are vines, but some are shrubs, annuals, perennials and even trees. What they all share are exotic flowers that only remain open for about 1 day. They have a wide, flat petal base with several rings of filaments in the center which surround a stalk of sorts, that holds up the ovary and stamens.
Flowers: 5 or 10 petals in a flat or reflex circle. The ovary and stamens are held atop a tall, distinctive stalk which is encircled by delicate filaments. The stigmas start out high above the anthers and slowly bend backwards to come closer for pollination. Colors include: blue, purple, pink, white and red.
Foliage: The most commonly grown forms are vines that climb and cling by tendrils. The leaves are alternate and either lobed or ovate.
The family Passifloraceae has a pantropical distribution. Passiflora itself is absent from Africa, where many other members of the family Passifloraceae occur (e.g. the more plesiomorphic Adenia).
Most species are found in South America, eastern Asia, southern Asia and New Guinea. Nine separate species of Passiflora are native to the United States, found from Ohio to the north, west to California and south to the Florida Keys. Four or more species are also found in Australia and a single endemic species in New Zealand. New species continue to be identified: for example, P. pardifolia and P. xishuangbannaensis have only been known to the scientific community since 2006 and 2005, respectively.
Some species of Passiflora have been naturalised beyond their native ranges. For example, blue passion flower (P. caerulea) now grows wild in Spain. The purple passionfruit (P. edulis) and its yellow relative flavicarpa have been introduced in many tropical regions as commercial crops.
What are the potential benefits of passionflower?
According to the National Center for Complementary and Integrative Health (NCCIH), more research is needed to assess the potential uses of P. incarnata. Some studies suggest it may help relieve anxiety and insomnia. Other species of passionflower have shown promise for treating stomach problems.
It may calm your mind
P. incarnata has many common names, including purple passionflower and maypop. Early studies suggest it might help relieve insomnia and anxiety. It appears to boost the level of gamma-aminobutyric acid (GABA) in your brain. This compound lowers brain activity, which may help you relax and sleep better.
In a trial published in Phytotherapy Research, participants drank a daily dose of herbal tea with purple passionflower. After seven days, they reported improvements in the quality of their sleep. The researchers suggest that purple passionflower may help adults manage mild sleep irregularities.
Some trials suggest that purple passionflower may also relieve anxiety. A study reported in the journal Anesthesia and Analgesia examined its effects on patients scheduled for surgery. Patients who consumed it reported less anxiety than those who received a placebo.
It might soothe your stomach
Other members of the Passiflora family might help treat stomach problems. Passiflora foetida is more commonly known as stinking passionflower. In a study reported in the Indian Journal of Pharmacology, researchers examined its potential for treating stomach ulcers. They found it helped alleviate ulcers in rats. It also showed antioxidant potential.
In another study reported in BioMed Research International, scientists examined Passiflora serratodigitata. They created an extract from its leaves and stems. This extract also showed promise for treating ulcers in rats. But more research is needed on humans.
What are the potential risks?
According to the NCCIH, passionflower is generally considered safe. But it may cause some side effects, such as sleepiness, dizziness and confusion.
Because of this, it should not be taken with sedative medications. Also, it’s not safe for pregnant women or breast-feeding women. It may induce contractions if you’re pregnant.
How can you take passionflower?
You can add dried passionflower to boiling water to create an herbal tea. You can find dried passionflower or prepackaged tea at many health food stores. You can also find liquid extracts, capsules, and tablets.
Always talk to your doctor before trying passionflower as an alternative treatment. They can help you assess the potential benefits and risks.
Passion flower growing tips
Sun: Passion flowers need at least 4 full hours of sunlight a day; more in cooler climates and some partial shade in the hottest areas. Plants may need winter protection in Zone 6. In zones cooler than zone 6, they will be winter-killed, unless you bring them indoors.
Soil: The soil should be well-draining, but rich. Passion flowers grow and bloom best when the soil is kept moist. They don’t handle drought well. Soil pH can be in the neutral range, anywhere from about 6.1 to 7.5.
Planting: The addition of compost to the planting hole will help retain moisture. Some type of support is needed for the vines to grow on. It can be a trellis, a structure or even another plant.
Most varieties of passion flower can be purchased as plants. They can also be propagated from either seed, softwood cuttings, layering or rhizomes.
Growing Passion Flower from Seed
To save seed, allow the fruits to ripen completely. Open the pods and remove, clean and dry the seeds before storing.
Passion flowers seeds can be difficult to sprout and hybrid varieties will not grow true from seed. Start seed by soaking for 1-2 days in warm water. Viable seed will sink to the bottom of the glass. Floating seeds can be discarded.
Start seed in damp potting mix. Place seed on surface of soil and pat down, but don’t cover. They need to be exposed to light, in order to germinate. Place the pot in a plastic bag and seal to retain moisture. If you can provide bottom heat to the pot, you’ll have a better chance of sprouting. A heat mat or even the top of a refrigerator should work.
It can take weeks or months for passion flower seeds to sprout. Keep the soil moist at all times. When sprouts do appear, keep them out of direct sunlight until there are true leaves and don’t handle the plants until they are large enough to transplant, with several sets of leaves.
Many species have been found to contain beta-carboline harmala alkaloids, some of which are MAO inhibitors. The flower and fruit have only traces of these chemicals, but the leaves and the roots often contain more. The most common of these alkaloids is harman, but harmaline, harmalol, harmine, and harmol are also present. The species known to bear such alkaloids include: P. actinea, P. alata (winged-stem passion flower), P. alba, P. bryonioides (cupped passion flower), P. caerulea (blue passion flower), P. capsularis, P. decaisneana, P. edulis (passion fruit), P. eichleriana, P. foetida (stinking passion flower), P. incarnata (maypop), P. quadrangularis (giant granadilla), P. suberosa, P. subpeltata and P. warmingii.
Other compounds found in passion flowers are coumarins (e.g. scopoletin and umbelliferone), maltol, phytosterols (e.g. lutenin) and cyanogenic glycosides (e.g. gynocardin) which render some species, i.e. P. adenopoda, somewhat poisonous. Many flavonoids and their glycosides have been found in Passiflora, including apigenin, benzoflavone, homoorientin, 7-isoorientin, isoshaftoside, isovitexin (or saponaretin), kaempferol, lucenin, luteolin, n-orientin, passiflorine (named after the genus), quercetin, rutin, saponarin, shaftoside, vicenin and vitexin. Maypop, blue passion flower (P. caerulea), and perhaps others contain the flavone chrysin. Also documented to occur at least in some Passiflora in quantity are the hydrocarbon nonacosane and the anthocyanidin pelargonidin-3-diglycoside.
The genus is rich in organic acids including formic, butyric, linoleic, linolenic, malic, myristic, oleic and palmitic acids as well as phenolic compounds, and the amino acid α-alanine. Esters like ethyl butyrate, ethyl caproate, n-hexyl butyrate and n-hexyl caproate give the fruits their flavor and appetizing smell. Sugars, contained mainly in the fruit, are most significantly d-fructose, d-glucose and raffinose. Among enzymes, Passiflora was found to be rich in catalase, pectin methylesterase and phenolase.