The Passifloraceae or Passion Vine Family is a relatively small family with approximately 36 genera and about 930 species. Passion Vine species are primarily from tropical regions and include trees, shrubs, lianas and vines (woody or herbaceous) or climbing plants.
Shared characteristics include some members with tendrils originating from leaf axils (other species grow erect), leaves spiraling along the stems, leaves stipulate. Flowers are radially symmetrical with 3 to 5 petals, sepals and stamens. Fruits are capsules or berries.
The family gets its name from the genus Passiflora, the largest in the family with over 500 species. Passion flowers are well known for their beautiful, showy and dramatic flowers all similar and yet each unique in color and size.
Important members of the passion flower genus include the edible passion fruit (Passiflora edulis) native to Brazil, Paraguay and northern Argentina. The passion fruit is a pepo, a type of berry with soft to firm and juicy inside with many seeds. Passiflora edulis serves as the exclusive host for the gulf fritillary larva and is also a non-exclusive host to the variegated fritillary butterfly.
Also included in Passiflora are the popular ornamentals including purple passionflower or "Maypop" (Passiflora incarnate) and "Running Pop" (Passiflora foetida). Passiflora incarnate is a hairy species and common wildflower in the southern United States.
According to the USDA Plants.gov site, the North America flora has 1 genus represented from this family, Passiflora with approximately 50 species. 14 species are found in the southwest United States;