Mythology:
Legend has it that in 1620 a Jesuit priest in Peru came across the plant we now know as passion flower. Enthralled with its beauty, that night he had a vision likening its floral parts to the elements of the Crucifixion or Passion of Christ. The five petals and five sepals became the ten apostles (omitting Peter and Judas). The three pistils became the nails of the cross; the purple corona (or filaments) was the crown of thorns, and the stemmed ovary was the Lord's goblet.
Links to Passion Flower mythology:
Passion Flower - Name and Symbolism
Symbolism of the Passion Flower