Passionflowers

 

Flower of Passiflora incarnata, the Purple Passionflower.
Rowan County, North Carolina. 

Passionflower flowers are as beautiful as they are complex.  They are classified in the genus Passiflora, a group of plants found mainly in the neotropics which is home for more than 500 species of passionflowers.  Two passionflowers are found in the Southeastern United States, Purple Passionflower, Passiflora incarnata and Yellow Passionflower, Passiflora lutea. 

The flowers have five sepals and five petals that are similar in shape and color.  Above the sepals and petals is a ring of long filaments called the corona. Arching from the center of the flower over the corona are five, pollen producing, stamens.  Then above the stamens are the carpels with three stigmas, the female flower parts that receive pollen. 

This striking flower structure caught the attention of early Spanish missionaries in the New World.  To these holy men, the flower was telling the story of the passion of Jesus. The five sepals and petals represented the ten faithful disciples.  Judas was left out for betraying Jesus and St. Peter; the founder of the Catholic Church, was not represented by a sepal or a petal because he denied Jesus on the night of his arrest.  The corona of filaments stood for the crown of thorns, the five stamens for Jesus's wounds on the cross and the three stigmas represented the three nails used in the crucifixion.  This religious interpretation of floral structure is how the plants got their name. 

Flower bud of Purple Passionflower.
Rowan County, North Carolina.

Purple Passionflower bud opening.
Rowan County, North Carolina. 

Purple Passionflower bud as it opens showing sepals,
petals and filaments of the corona. 
Rowan County, North Carolina. 

        

Fully open Purple Passionflower.
Rowan County, North Carolina.

Passiflora incarnata, the Purple Passionflower, is an herbaceous vine with three-lobed leaves.  The plant can ramble across the ground and produce tendrils that allow it to grow over other plants.  As its name suggests, the flower has purple sepals and petals.  The filaments are banded with purple and white while the stamens and carpels are yellow-green.  Passionflowers are pollinated by bees and develop large, green edible fruits.   

Three-lobed leaf of Purple Passionflower.
Rowan County, North Carolina. 

A Carpenter Bee (Xylocopa sp.) pollinating Purple Passionflower. 
The bee is collecting nectar as a stamen of the flower
 is depositing pollen on its back. 
Rowan County, North Carolina.

Two Purple Passionflower fruits. 
Rowan County, North Carolina. 

Yellow Passionflower (Passiflora lutea) is the second species in our area. Like Purple Passionflower, Yellow Passionflower is also a vine and its leaves have three lobes.  Yellow Passionflower is not as showy as the Purple Passionflower and has small yellow flowers.  But these flowers have the same complex structures as Purple Passionflower.  

Yellow Passionflower (Passiflora lutea) with its
rounded, three-lobed leaves and small yellow flower.
Rowan County, North Carolina. 

Yellow Passionflower has the same flower structure as its
more colorful relative, the Purple Passionflower.
Rowan County, North Carolina. 

Passionflower is the host of Gulf Fritillary butterflies (Agraulis vanillae).  These beautiful butterflies lay their eggs on the leaves of Passionflowers.  The eggs hatch and the larvae eat the leaves and transform into a chrysalis that hangs on the stems.  After a few weeks the adult butterfly emerges and feeds on the nectar of many plant species.  The bright orange color of the Gulf Fritillary is advertising its unpalatability.  Predators avoid this butterfly because it contains noxious chemicals that the larvae collected while eating Passionflower leaves.  Even the caterpillars of Gulf Fritillary advertise their toxicity with their bright orange color and black spikes. 

Gulf Fritillary (Agraulis vanillae) caterpillar on Purple Passionflower.
Rowan County, North Carolina. 

Passionflowers thrive in the hottest summer months. Even in the midst of a drought they bring on the those great flowers. So while many plants are riding out the heat, passionflowers put on their show.

Adult Gulf Fritillary.
Rowan County, North Carolina.