The passionflower, Passiflora, is a climbing vine of the American tropics bearing an intricate and unmistakable flower, and its name records one of the most elaborate readings ever given to a plant. Spanish missionaries in South America in the sixteenth and seventeenth centuries saw in the flower a complete emblem of the Passion of Christ and used it to teach the crucifixion: the fringed corona became the crown of thorns, the three stigmas the three nails, the five anthers the five wounds, the ten petals and sepals the ten faithful apostles (Peter and Judas set aside), and the coiling tendrils the cords and whips.
The elaborate symbolic reading was first written down in 1609 by the Italian writer Jacomo Bosio, in Rome, who had been shown a passionflower and told of its meaning by a Mexican friar recently returned from the missions, and Bosio's account, expanded with further correspondences by writers who came after him, became the standard version repeated in devotional literature and garden books for the next four centuries. The passionflower's vine, which climbs by clinging tendrils and can cover a considerable area in a single season, gave missionaries an additional practical advantage: a fast-growing, visually arresting plant that could be pointed to directly, growing wild, made a far more vivid teaching aid than any painted image brought from Europe.