Florida Passionflowers

Few flowers which frequent our Nature Preserves in Hillsborough County rival the alien beauty of the passion vine. But, far more than just an ornament, this diverse genus of species (Passiflora) plays an important role in nature, as well as your garden and pantry!

Two clouded skipper butterflies (Lerema accius) visit a Maypop passionflower. Photo by Bill Carlisle.

Grocery store aficionados are likely familiar with passion fruit and passion fruit juice, and some may recognize passionflower tea or passionflower sleep aids. These are indeed all products of Passiflora plants. Most of the fruit and juice production in the United States comes from the species Passiflora edulis. This Brazilian plant is widely cultivated in Florida, but not native to North America. However, its close relative Passiflora incarnata, or maypop, is.

left is the Brazilian edulis vine and on the right, the native maypop (incarnata). Photos by Meagan Arnold and Brady Reed, respectively.

Maypop plants have made their way all around the world, and their flowers are used frequently in traditional herbal medicine. Passionflower tea, a staple at most groceries, is made using this Florida native plant and advertises benefits to sleep and the reduction of anxiety. Scientific research has uncovered a plethora of pharmacological activities in maypop which lend credibility to its sedative effects, and the area of research is ongoing.

A maypop vine bearing fruit while growing over a Eupatorium bush. 

Like the edulis, maypop have prominent, edible fruit, but they are smaller and contain less juice. Despite this, the cultivation of maypop for juice production and consumption seems common in much of the world, paradoxically except in the United States.

A maypop growing in an Eupatorium bush right along the Hillsborough County Hiking Spree "Second Chance Trail" at Bell Creek Nature Preserve.

Maypop is a common sight in well-managed natural lands, such as those found in Hillsborough County’s nature preserves. The sprawling vine prefers full sunlight, and grows well in open, fire-dependent ecosystems, such as meadows, sandhill, and pine flatwoods.

The much smaller corkystem passion vine also bears edible fruit. Its delicate flowers are a miniature of the maypop. Left photo by Ben Keen, right photo by Zoltán Stekkelpak.

Just as humans eat the fruit and flowers from the plant, animals such as the wild turkey also depend upon the maypop fruit as a food source in the summer and fall. Another native passion vine, corkystem passion vine (Passiflora suberosa), is an excellent means for attracting songbirds to your garden. This species’ fruit are small, purple, and totally irresistible to birds. The corkystem is easy to grow in shady areas, and can be planted at the base of larger, more ornamental plants. However, when exposed to direct sunlight, they can thrive as a dense, green, attractive vine.

A carpenter bee nectars at a maypop passionflower. Yellow pollen can be seen covering her back, distributed effectively by the well positioned, broom-like anthers. Photo by Bill Carlisle.

The corkystem’s flower is less ornate than its larger cousins, but both the maypop and the corkystem are exceptional pollinator plants. Their flowers prove to be desired haunts for our native carpenter bees (Xylocopa sp.), and both vines are an important source of pollen and nectar for insects in nature areas as well as gardens. A healthy and active pollinator population is essential to these vines. Passiflora plants are generally obligate outcrossers, meaning they require pollen from another individual to reproduce, an important consideration for fruit production!

The zebra longwing, the Florida state butterfly, requires Passiflora vines to reproduce. Photo by Adam Jackson

This dependency on pollinators is reflected, and inverted, in a peculiar relationship with butterflies. Both of our Hillsborough County native Passiflora, the maypop and the corkystem, are larval hostplants to several butterflies. The gulf fritillary (Agraulis vanillae), zebra longwing (Heliconius charithonia), variegated fritillary (Euptoieta claudia) and julia butterfly (Dryas iulia) are dependent on Passiflora species for their caterpillar's food. Thus, maypop and corkystem are popular choices for butterfly gardens. Growing either of these species, you are nearly guaranteed to see gulf fritillary and zebra longwing butterflies’ constant presence.

A julia butterfly caterpillar. Photo by Jade Fortnash.

Keeping Passiflora in suitable pollinator gardens helps to create corridors between natural areas, but your selection of species does matter. We strongly recommend using regionally native species, such as maypop and corkystem, in your butterfly gardens. Butterflies are known to find their host plants by scent, and recent research indicates that zebra longwing butterflies, for instance, show a strong preference for the specific species they fed on as caterpillars. Therefore, while exotic Passiflora like edulis might seem attractive, they may not be as appealing to native butterflies and could potentially foster a butterfly population overly reliant on non-native plants. Such a scenario could lead to a less diverse butterfly population and introduce unpredictable elements into the broader ecosystem.

It is important to note that there are a variety of native and non-native Passiflora. Knowing the differences can help you build a more sustainable garden. On the left is the South-Florida native multiflora and on the right is the South-American glandulosa. Left photo by Judy Gallagher CC by 4.0. The right photo is by Acevedo-Rodriguez, P.

Like the monarch butterfly (Danaus plexippus) with its milkweed (Asclepias sp.), caterpillars of certain species can be voracious, defoliating Passiflora plants. To mitigate this, position large passion vines like maypop in open, sunny areas and surround them with a diversity of nectar plants. This opens opportunities for natural avian and insect predators to thin out the caterpillar population, ultimately leading to improved outcomes for the surviving caterpillars and cycling nutrients up the food chain to support bird reproduction.

Mary Vaux Walcott, Maypop (Passiflora incarnata), 1926, watercolor on paper, Smithsonian American Art Museum.

The maypop’s large, lacy flower is instantly recognizable on the trail, but not always present. Familiarizing yourself with the distinctive three-lobed leaves of passion vines and their associated butterflies, like the zebra longwing and gulf fritillary, can enhance your experience in nature, and as you enjoy our trails during the 2023-2024 Hillsborough County Hiking Spree, take a moment to appreciate these native plants.