It is very, very easy to fall in love with passionflowers (Passiflora), all two hundred species. A friend who as a collector of these strange beauties put it, "I am just passionate about passionflowers!" But these vines were not named for how the collectors feel.

It is said that a Spanish doctor, Monardes, discovered passionflowers (Passiflora edulis) in 1569 while traveling in South America. Of course, the natives of the Amazon already knew of these vines and called them maracuja. The Incas, the Aztecs, the Mayans, and many of the native peoples of the Americas knew of passionflowers and had medicinal uses for the plants. In Virginia, the vine was called maracoc. The similarity of names from the Amazon to the eastern seaboard indicates that the natives had been using and discussing these vines for a very long time. But Monardes was the one to introduce the passionflower and its medicinal uses to Europe.

Thirty-four (or more) secondary chemical compounds have been identified in the genus Passiflora. Secondary compounds are those chemicals a plant produces that do not have a direct role in the life and growth of a plant, but benefit the plant in some other way. An example is Passiflora incarnata; the crushed leaves smell terrible and taste worse. The taste and smell is a warning, for one of the nastier toxins found in Passiflora is a cyanogenic glycoside. Most herbivores are smart enough not to eat them. A plant that does not get eaten is more likely to survive and reproduce.

Native American medicine used the leaves of the maracoc as a sleep aid, to calm hysteria and convulsions, to relieve headaches, bronchitis, colic, and diarrhea. Poultices of leaves were applied to bruises and contusion injuries. Today, extracts from Passiflora are used in some types of sleeping pills.

The Spanish living in the West Indies called these plants granadilla, because the delicious fruit somewhat resembles the granadas or pomegranate. The botanical and common names came in a roundabout way. These names were derived from Flos Passionis, a name bestowed upon these plants by the Spanish friars who came to the Americas to convert the Native Americans to Catholicism. With the differences in languages, the friars needed teaching tools and the passionflower made for good symbolism when teaching of the suffering and crucifixion of Christ.

The Spanish friars' legend of the passionflower runs thus: The three bracts at the base of the flower represent the trinity of God. The ten petal-like structures represent the ten apostles present at the crucifixion, Peter being absent because he denied Christ and Judas because he betrayed Christ. In some versions, the fringe petals represent the lash wounds from the whips of the Romans, in other versions; they represent the crown of thorns. The five anthers signified the wounds to Christ's body. The three stigmas at the top represent the nails in the hands and feet.