The hallmark of the genus is the androgynophore, a central column to which the stamens and pistil are attached, which can be very long in some species such as Passiflora coactilis.

[5] 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.

[13] Passiflora has a largely neotropic distribution, unlike other genera in the family Passifloraceae, which includes more Old World species (such as the genus Adenia).

[15] The purple passionfruit (P. edulis) and its yellow relative flavicarpa have been introduced in many tropical regions as commercial crops.

Pollinators of Passiflora include bumblebees, carpenter bees (e.g., Xylocopa sonorina), wasps, bats, and hummingbirds (especially hermits such as Phaethornis); some others are additionally capable of self-pollination.

The many defensive adaptations visible on Passiflora include diverse leaf shapes (which help disguise their identity), colored nubs (which mimic butterfly eggs and can deter Heliconians from ovipositing on a seemingly crowded leaf), extrafloral nectaries, trichomes, variegation, and chemical defenses.

Since the insects usually killed are rarely major pests, this passion flower seems to be a protocarnivorous plant.

Blue passion flower (P. caerulea) is an invasive species in Spain and considered likely to threaten ecosystems there.

For example, the Chilean passion flower (P. pinnatistipula) is a rare vine growing in the Tropical Andes southwards from Venezuela between 2,500 and 3,800 metres (8,200 and 12,500 ft) in altitude, and in Coastal Central Chile, where it only occurs in a few tens of square kilometres of fog forest by the sea, near Zapallar.

P. pinnatistipula has a round fruit, unusual in Tacsonia group species like banana passion flower and P. mixta, with their elongated tubes and brightly red to rose-colored petals.

[28][4] Consuming passion flower products may cause drowsiness, nausea, dizziness, abnormal heart rhythms, asthma, or rhinitis.

Many cool-growing Passiflora from the Andes Mountains can be grown successfully for their beautiful flowers and fruit in cooler Mediterranean climates, such as the Monterey Bay and San Francisco in California and along the western coast of the U.S. into Canada.

One blue passion flower or hybrid even grew to large size at Malmö Central Station in Sweden.

A native source of beta-Carbolines (e.g., passion flower in North America) is mixed with Desmanthus illinoensis (Illinois bundleflower) root bark to produce a hallucinogenic drink called prairiehuasca, which is an analog of the shamanic brew ayahuasca.

[38] Passiflora incarnata (maypop) leaves and roots have a long history of use as a traditional medicine by Native Americans in North America and were adapted by European colonists.

Older Germanic names[43] include Christus-Krone ('Christ's crown'), Christus-Strauss ('Christ's bouquet'),[44] Dorn-Krone ('crown of thorns'), Jesus-Lijden ('Jesus' passion'), Marter ('passion')[45] or Muttergottes-Stern ('Mother of God's star').

In Hawaiian, they are called lilikoʻi;[47] lī is a string used for tying fabric together, such as a shoelace, and liko means 'to spring forth leave'.