Passiflora, known also as the passion flowers or passion vines, is a genus of about 500 species of flowering plants, the namesakes of the family Passifloraceae. They are mostly vines, with some being shrubs, and a few species being herbaceous.
Nine species of Passiflora are native to the USA, found from Ohio to the north, west to California and south to the Florida Keys. Most other species are found in South America, China, and Southern Asia, New Guinea, four or more species in Australia and a single endemic species in New Zealand. New species continue to be identified: for example, P. pardifolia and P. xishuangbannaensis have only been known to the scientific community since 2006 and 2005, respectively.