One of the southeast’s early summer wildflowers is Tennessee’s official state wildflower: Passiflora incarnata, the purple passion flower. The fruit of this species also gives this plant one of its other common names – Maypop.
Known to the Cherokees, according to Wikipedia, as “Ocoee,” this plant would then be the namesake for one of the southeast’s most famous whitewater rivers, the Ocoee River of southeastern Tennessee.
The fruit of P. incarnata is not considered edible, but the whole plant has been used as a herbal medicine to treat nervous anxiety and anxiety, administered by drying and grinding the plant and putting a teaspoon in tea (also from Wikipedia.)
[UPDATE 07/14/2009: I have seen several places that list P. incarnata's fruit as edible. My previous statement that it isn't considered edible was based on some places not including it in their list of edible species, and my experience with the fruit as a child - it didn't seem to contain anything I would want to eat. In retrospect, I may have never inspected the ripe fruit of P. incarnata, but I hope to be able to harvest at least one ripened fruit from the colony I am watching near my home. If I am able to do so, I'll make a report later on my "edibility findings."]
[Update 07/29/2009: Unfortunately the Georgia DOT mowed the ditch/roadside where 'my' colony of passion flower was growing. I don't think any of the plants with developing fruit survived. I need to find another colony if I'm going to test the palatability of the fruit.]
[Update 10/25/2009: See the post from 10/25/2009 for a report on edibility.]
Unlike P. incarnata, there are about 60 species of passion fruit which produce edible fruit. The most commonly eaten of these is Passiflora edulis, which is also known as purple passion fruit, both for the color of the blossom and for the color of the ripened fruit. This plant is best grown in the higher elevations of the tropics, but is known in Florida and Georgia, including Walker County. I believe P. edulis is the species I ate (delicious!) and photographed while in the Papua New Guinea highlands last June.
Be sure to check out the other Passionflower articles on USWildflowers.com.