maypop is a common name for passiflora incarnata. yep, same thing.

if the seeds are not yet black you will find that the fruit is not ripe.

~Chills

They don't really get pulp but the seeds are surrounded by arils that are filled with juice when ripe. I think it smells kind of like Hawaiian Punch (which I think is flavored with passion fruit).
Karyn

"Passion fruit" is somewhat of a generic term for any fruit from a Passiflora, but is most commonly used for the commercially grown fruit from P. edulis. Maypops are closely related, and some taste similar to P. edulis when fully ripe. In order to taste a ripe one, you will need to let the fruit drop off the vine on its own. Don't pick it. After it falls off, let it sit in a cool dry spot indoors for a few days until the outside starts to wrinkle. At this stage, it should be as good as it will get. I find that most maypops have a "Hawaiian Punch" type of flavor, but also an unpleasant aftertaste.