Purple Passionflower Maypop Passiflora incarnata – Native Plant of the Week

Introduction

Maypop, Purple Passionflower Passiflora incarnata is a gorgeous vine native throughout the eastern USA. Like all passion flowers its beautiful flowers are unique and characteristic of the Passiflora genus. It is a fairly vigorous vine with pretty leaves and can grow in a multitude of places. It has a long interesting use by the indigenous people of North America. The Cherokee in particular have a long cultural history with this plant and who have likely been cultivating them for at least 3000 years.

I found my first Passiflora incarnata plant on the edge of a sidewalk in Nashville, TN, USA. Seeing its beautiful, large lovely flower growing happily in among the nonnative grasses was exciting for me. I always love to see beautiful native species that are tough enough to grow in the difficult conditions created by humanity. It gives me a lot of respect for those plants that were here long before us, but yet continue to thrive here despite us. If I lived in that area I would fill my garden and cover my fences with this lovely native vine. The added bonus is that it is also a host to so many gorgeous native butterflies so it would make a perfect addition to any butterfly garden as well. See section on Growing Purple Passionflower in Your Garden below.

Description of Maypop or Purple Passionflower

Stem & Leaves

Maypop is a herbaceous perennial vine 6 – 9 m in length that dies back each winter. It is a tendril climber with numerous tendrils it produces from its axils along the length of its stem. The tendrils are used to cling onto surfaces allowing it to climb. The stems are terete in cross-section and they may be either pubescent or hairless. It grows from a deep and far-spreading fibrous root system that regularly produces suckers that help it spread vegetatively.

The leaves are arranged alternately on the stem. They are deeply 3(-5) palmately lobed and roughly symmetric, 4 – 12 (-22) cm by 4 – 12 (-30) cm in size. The middle lobe may or may not be longer than the lateral lobes. Their leaves’ edges are finely toothed and their lower side veins are prominently raised. They may be sparsely to moderately hairy and are somewhat pungent in smell. They have linear-setaceous stipules that are 3 – 5 mm by 0.5 mm in size. The leaves are petiolate (having leaf stalks). Their petioles have two characteristic glands at their base that are pungent in smell.

Flowers & Fruits

The flowers appear from April – October, but depending on location can occasionally be seen flowering in March or November. The large flowers are approximately 5 cm in diameter and are borne singly on a long peduncle (flower stalk). They are fragrant with a pleasant odor. The calyx consists of 5 white sepals that are partially joined (connate) at the base. There are 5 bluish-white petals arranged alternately between the sepals that may or may not appear similar in size and color to the sepals. Next, there is a corona of wavy purple fine filaments radiating out from the center between the petals and the reproductive organs. The filaments in some rare cases may even be white. This corona of filaments is a unique feature characteristic of the entire Passiflora genus.

The reproductive organs are frequently as showy as the corona of filaments and add to the unique beauty of this genus. Purple Passionflower has 5 whitish to yellow stamens with horizontally attached whitish to yellow anthers. The stamens are arranged centrally in the middle of the flower. In the very center of the flower on the inside of the stamens is an ovary with 3 styles topped with stigmas that radiate outwards in a central whorl.

Its fruit is often referred to as a Maypop or a granadillo. It is a green or greenish-yellow berry about the size of an egg that turns orange when ripe. The common name Maypop apparently comes from the fact that the fruits “may pop” when you step on them. Depending on the maturity of the vine there may be as many as 10-20 egg-sized fruits on a single vine. The fleshy arils around the seeds are edible and vary in flavor but are potentially quite sweet and tasty.

Similar Species Frequently Confused With

Passiflora incarnata in its flowering state is virtually impossible to confuse with any other genus as Passiflora flowers all have such unique flowers. However, they could be misidentified within the Passiflora genus. In its native range there are multiple Passiflora species both native and introduced. However, the majority of them have tiny flowers by comparison (1 – 2 cm diameter at the most compared to the 5 cm diameter of Passiflora incarnata). The other Passiflora species’ flowers are almost exclusively whitish to yellow in color making them difficult to mistake them for P. incarnata. There are however two introduced species found so far only in Florida that have naturalized in a few locations, that could potentially be mistaken for Passiflora incarnata. The differences are as follows:

• Passiflora edulis – this one has larger stipules, to about 10 mm long, more coarsely serrated leaf margins, larger leaf-like floral bracts to 17 x 8 mm in size, and an androgynophore base that is expanded much more abruptly as opposed to gradually. It has a limited distribution in the USA, it is found naturalized only in southern Florida. However, it is frequently cultivated for its edible fruits.
• Passiflora “Incense” is an artificial hybrid between P. incarnata and P. cincinnata from South America. It is only found in cultivation but could be confused in gardens with P. incarnata. It differs from P. incarnata in its five-lobed leaves and larger floral bracts that are 15 x 10 mm in size.

Distribution of Maypop Passiflora incarnata

Purple Passionflower is found only in the eastern USA. It is not present in Canada, Mexico, or anywhere else globally in the wild. However, it is popular in Europe as a garden plant for its beautiful flowers and its popular use in herbal medicine.

In the USA, Maypop is found in Kansas, Oklahoma, Texas, Missouri, Arkansas, Louisiana, Illinois, Indiana, Ohio, Kentucky, Tennessee, Mississippi, Alabama, Georgia, Florida, South Carolina, North Carolina, Virginia, West Virginia, Delaware, Maryland, Washington DC, Pennsylvania, and New Jersey. In Tennessee, it is the state wildflower.

Habitat & Growing Conditions of Purple Passion Flower

Maypop grows in open woods, prairies, savannas, dunes, pastures, fields, riverbanks, and disturbed areas such as roadsides, railroads, cleared land, and other human disturbances. It grows in a number of soil types including clayey, loamy, sandy, dry to moderately moist. It is highly tolerant of drought but can even occasionally tolerate wet and acidic soils. Maypop is tolerant of full sun and partial shade. It will not grow in the full shade of a forest canopy.

It is often found growing in very poor soil in disturbed areas. Because of this, its range has likely been expanding. For instance, it has been found sporadically growing north of southern Illinois and southern Ohio which were considered its most northern limit previously. It is able to spread over large areas due to suckers from its deep, spreading roots.

Growing Purple Passionflower in Your Garden

Growing species native to your area is a great addition to your garden. Once established they require little to no maintenance of any kind. They already grow in your area without water or fertilizer, so they will easily grow in your yard if you live in their range. They also provide important wildlife and biodiversity values as well as the aesthetic beauty they provide.

Choose a nice sunny location. If you live in a particularly hot area try to choose a spot that gets a bit of afternoon shade when the sun is hottest. Plant the plants or seeds in loamy well-drained soil. If your yard has poor soil they will still grow in it but you should mulch them annually with organic compost in order to provide them with food to give you better blooms and a better fruit harvest.

If your soil is clayey or wet however you will need to dig out a pit of soil approximately 75 cm cubed and place gravel in the bottom then fill it with sandy loam and create a mound to plant your plant or seeds in to provide it with better drainage as they will not grow well in waterlogged soils.

Finally, you will need a trellis, fence, arbor, or some other structure for your vines to climb on as they grow each spring.

Pests

Aphids, white flies and spider mites may all infect your vines. If this happens you can treat them with diluted neem oil. It is a potent natural insecticide that will not harm the plant.

Winter Maintenance

Because the plant is a herbaceous perennial it will die back in the winter at which time you can cut the vines back to the ground. If there are still fruits on the plant that were not eaten however, try leaving them for winter forage for wildlife and cut them down once the fruits are all gone.

If you live in an area with particularly cold winters you can grow your plants in large pots and store them indoors or in a garage for the winter, then put them out each spring. Alternatively, you can add a winter mulch to the top of the soil to protect the roots in the ground for the winter.

Wildlife Values

Like most Passiflora species Passiflora incarnata is host to many native butterfly species. These include Heliconius charithonia the zebra longwing, Heliconius erato the red postman or crimson-patched longwing, Dryas iulia or the Julia butterfly, Paratrea plebeja the plebeian sphinx moth, and Euptoieta claudia the variegated fritillary butterfly. It is also the exclusive host for the Gulf Fritillary Dione vanillae.

A number of animals and birds eat the fleshy seeds including deer, rabbits, wild turkeys, and several native bird species. Wild turkey and deer are also known to eat the vines themselves. Bees and hummingbirds are both known to frequently visit the flowers for the nectar they contain.

Status of Passiflora incarnata

Purple Passionflower is considered Globally Secure, G5.

In the USA Purple Passionflower is considered Locally Secure S5 in Virginia and North Carolina. In Kentucky it is Apparently Secure S4. It is Vulnerable S3 in Indiana. It is considered Imperiled S2 in West Virginia and Ohio. In all other states where it is found it is unranked.

Maypop is not found in either Canada or Mexico.

Traditional or Other Uses of Maypop or Purple Passionflower

Purple Passionflower as Food

Purple Passionflower was widely used by the Cherokee people in the eastern USA and to this day is still an important part of their cultural heritage. They called it Ocoee which is where the Ocoee River and valley in Tennessee got their name. It is believed that they cultivated the plant for as much as 3000 years before the arrival of Europeans. The fruit was frequently eaten raw while the leaves were parboiled then fried with grease and salt and eaten as a potherb. Young shoots and leaves were also boiled and fried and eaten with other greens. They also crushed the fruit and made it into a popular beverage.

Passiflora incarnata Medicinal Uses

The Cherokee people also used Passiflora incarnata for multiple medicinal purposes. As a dermatological aid, the pounded roots were used to draw out inflammations while an infusion of the roots was used to treat boils. Sometimes the leaves were used in a poultice to treat burns and wounds. An infusion of the roots was given to babies to aid in weaning. A warm infusion of the beaten root was dropped into the ear to treat earaches. The Cherokee also used an infusion of the roots to treat problems with the liver. The Houma people would take an infusion of the roots as a blood tonic.

Herbalists often recommend an infusion of the roots to treat anxiety, seizures, hysteria, and insomnia. It is particularly popular as a herbal remedy to aid in a night of restful sleep. Recent studies have confirmed its ability to help induce a restful sleep.

Maypop as an Ornamental

Due to its vigorous growth habit, its tolerance to a variety of conditions, and its beautiful flowers Maypop is widely grown as an ornamental garden vine. It can easily be trained to grow up fences and arbors where it shows off its beautiful flowers and provides value for butterflies and other wildlife.

Ethical Wildcrafting of Passiflora incarnata

Check the status in your state before harvesting since it is imperiled or vulnerable in several states. See above section on Status. Alternatively, grow it in your garden for both its lovely leaves and flowers as well as its useful properties and wildlife values.

If you are harvesting Passiflora incarnata from the wild as always use the 1 in 20 rule of Ethical Wildcrafting. Pick one in every 20 flowers or leaves you see. If harvesting the roots dig up the roots of only one in every 20 plants you see in a healthy population. If possible dig around the side of the plant and only harvest some of its roots in an attempt to leave the plant alive once you are finished collecting the root. It has a prolific root system so this should not be an issue. Always harvest early or late in the day. Avoid harvesting in full sun as this reduces the quality of your harvest and increases the risk of damage to the plant.

Wildcrafting and Processing

Picked fruits, leaves, or roots can be placed in a basket, bowl, or paper bag and brought home for processing. If you are harvesting multiple products on the same day be sure to label the roots in a paper bag so that you do not confuse different plants.

Maypop can be eaten fresh or cooked upon picking. If using it medicinally, it can be dried for later use.

To dry the leaves simply place them on a rack or screen in a single layer and allow them to dry. Roots should be brushed clean of any dirt then chopped into more manageable pieces before drying. Dried roots are notoriously difficult to cut into smaller pieces once dried. If you are wanting to dry the fruits they will need to be cut into smaller pieces before drying to prevent rotting. Otherwise, they could also be dried more quickly in a food dehydrator on the lowest heat setting.

Once dried the leaves, fruits, and roots can be stored in a jar for later use. Label your jar with the species name and the date of harvest. I also usually add the location of harvest for my own reference. Do not grind or crush the leaves or roots until you are ready to use them. This keeps them as fresh as possible and preserves their medicinal properties. When you pre-grind, even if stored in glass jars, this increases the oxidation rate and rapidly degrades the medicinal properties.

References and Resources

Canadensys Plant Search https://data.canadensys.net/vascan/search

Dictionary of Botanical Terms – by Lyrae’s Nature Blog https://lyraenatureblog.com/blog/dictionary-of-botanical-terms/

Eflora Plants of North America http://www.efloras.org/browse.aspx?flora_id=1

Guerrero FA, Medina GM. Effect of a medicinal plant (Passiflora incarnata L) on sleep. Sleep Sci. 2017;10(3):96-100. doi:10.5935/1984-0063.20170018

iNaturalist Plant Search https://www.inaturalist.org/home

Native American Ethnobotany http://naeb.brit.org/

Natureserve Explorer https://explorer.natureserve.org/Search

USDA Plants Database https://plants.sc.egov.usda.gov/home

Wikipedia on Passiflora incarnata https://en.wikipedia.org/wiki/Passiflora_incarnata

Willis, Lyrae (2021).  Plant Families of North America.  Not yet published. 

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