No one could blame Midwesterners for thinking that this groovy-flowered vine with tropical fruits was an exotic brought in by an unsuspecting gardener. In fact, purple passionflower is a hardy native of Ohio! Many species of Passiflora grow natively in tropics around the world, but Passiflora incarnata is the non-tropical species of passion fruit native to the US. Yellow passionflower, Passiflora lutea, is another native that is less showy, with smaller, yellow flowers. Purple passionflower is a fast-growing vine that has unique three-lobed foliage; strikingly ornate flowers; and egg-shaped, tangy/sweet edible fruits. It grows best in full sun but will tolerate a bit of shade, reaching up to 25 or 30 feet in length. It’s adaptable to a wide variety of soils, including poor soils, and if sited in full sun and rich soil, its rhizomes will spread over large areas. The runners may be pulled up and transplanted or discarded to keep the vine in check. In hotter climates, purple passionflower is a woody plant, but in Ohio’s colder climate, the vines die back to the ground in winter. Southern Ohio is the northern limit of P. incarnata’s appearance in the wild, giving the plant a spot on the list of threatened species in Ohio; however, it occurs in cultivated gardens in other parts of the state. While the plant isn’t reliably hardy in our zone, its odds for survival are greatly improved in protected sites, such as near a wall or building.
The fascinating, sweetly fragrant flowers are infinitely varied and irresistible. When viewed from underneath, the green, oblong sepals and white petals are clearly seen. Viewed from above, the sepals and petals are visible through a corona of long, squiggly, white-to-purple fringes sporting bands of colors at their bases. In the center of it all is a prominent sculpture of oval anthers attached to oblong filaments, a plump ovary, and propeller-like styles with stigma “eyeballs.” The complex structure provides an efficient pollination process: an insect seeking nectar rubs against the base of an anther, coating its back with pollen. When the insect moves around on the flowers, the downward-curving stigmas pick up the pollen from the insect’s back. The resulting fruits develop during the 2 to 3 months after pollination, changing from green to yellow and maturing to the size of an egg or baseball. The sweet pulp tastes of citrus, and the ripe fruits can be eaten straight from the vine or made into jellies.
Catholic priests are thought to have supplied the common name because they associated parts of the plant with the story of the “Passion,” Christ's crucifixion. The species name, incarnata, means "in the flesh," or "incarnate." Another common name, "maypop," refers to the fruits, which make a popping sound when stepped on or crushed.
Native habitats include sandy soils, low and moist woods, stream banks, fencerows, disturbed areas, railroads, pastures, hayfields, and roadsides. The vine may be used to twine on trellises, arbors, walls, fences, or even on other plants.
Plant Characteristics:
Grows 6-25’ tall and spreads 3-20’.
Prefers full sun and tolerates light shade.
Prefers average to moist, well-drained soils, including clay, loamy, or sandy. Once established, it tolerates drought.
Fringed flowers arise singly from axils between June and September, followed by fleshy, yellowish fruits with edible pulp and seeds that mature to brown.
Alternate, dark-green leaves are 2 ½ to 6 inches long and nearly as wide with 3-5 lobes ending in sharp tips. Margins are finely serrated.
Green stems--either smooth or covered in short hairs--have tendrils that help the plant to climb. The heights of the vines vary greatly depending on soil, light, and the type of structure supporting the plant.
Wildlife Value:
Host plant to 4 species of Lepidoptera larvae in central Ohio: variegated fritillary butterfly (pictured here), Smith’s dart, subterranean dart, and plebian sphinx moths. Butterflies, bees, moths, bats, and hummingbirds visit for nectar and pollen.
Medicinal, Edible, and Other Uses:
Native Americans made great use of the plant. The roots were used to treat boils and to aid in healing wounds. Babies were fed a root tea to aid in weaning. The roots were also used as ear drops for earaches, as infusions to treat liver problems, and as a sedative to treat nervous conditions. Some research shows that compounds in the plant induce sleep and provide better sleep quality.
Native Americans ate the fruits raw or boiled them into a syrup. Crushed and strained fruits resulted in a beverage that was sometimes thickened with flour or cornmeal. The young shoots and leaves were cooked with other greens. The fruits, flowers, and leaves are edible. Ripe fruit has light green/yellow skin and feels heavier than immature fruit. The pulp around the large seeds is yellow when ripe. When fruits fall off the vine, they are overly ripe and sweet without the tang.