Its name comes from a family of passion flowers (passiflora).
In Portuguese it's called "maracujá," after an Native American word which is not so pleasant, so I'll skip it.
It's served either sweet or sour.
Technically it's a berry and one fruit has only 17 calories. The dark seeds are crunchy but edible.
The most popular varieties are purple and yellow. Purple ones are smaller but sweeter and are more commonly found here. Yellow ones are more sour and larger and they're Brazilians' favorite.
It's known to have calming properties and it's used as a sleeping aid, to calm nerves and relieve anxiety. So if you're feeling edgy, try it for a few days and see.
It's a source of vitamins A, C and B complex and has minerals as well: iron, sodium, calcium and phosphorous.