Passiflora foetida aka Mossy Passionflower

Passiflora foetida is native to the warm-temperate and tropical Americas, including the southwestern United States (southern Texas and Arizona), Mexico, Central America, the Caribbean, and most of South America from the Bahamas south to Argentina and Chile. It has been widely introduced and naturalized across tropical regions of Africa, Asia, the Pacific, and Australia, where it is often regarded as a weed.

Passiflora foetida is a perennial climbing or creeping vine with thin, wiry, sticky-hairy stems that become woody with age. It typically reaches around 2.5 m in length and can occasionally extend up to 5 m when supported. In warm tropical conditions it flowers and fruits year-round.

Passiflora foetida is adapted to warm climates and requires temperatures above 16 °C for successful fruit set. It thrives in tropical and warm-temperate regions across its native and naturalized range, where year-round flowering and fruiting are possible.

The flowers of Passiflora foetida are typically white to pale cream, pink, or pale purple, often with darker markings, and measure roughly 2–6 cm in diameter depending on the source. They are surrounded by finely divided, glandular-hairy bracts that give the species its "love-in-a-mist" common name. In suitable warm conditions it can flower throughout the year.

The plant's foliage emits a strong, pungent, unpleasant odor when crushed — the source of both its specific epithet "foetida" and the common names "stinking passionflower" and "goat-scented passionflower."

Passiflora foetida is a highly variable species with multiple recognized varieties showing different geographic distributions; var. foetida is the form occurring in New South Wales. Red-fruited plants from parts of the species' range have at times been classified as distinct species or varieties.

Outdoors, Passiflora foetida grows best in humus-rich, well-drained soil with dappled shade and warm temperatures (above ~16 °C). It is naturally found on rainforest margins, roadsides, and disturbed ground, and readily naturalizes in tropical regions, where it is widely considered a weed of plantations and natural areas.

Passiflora foetida can be propagated by seed, by softwood or hardwood cuttings, by layering, and by air layering. Seed dispersal also occurs naturally — birds eat the fruit and spread the seeds, which contributes to its weediness in the tropics.

A distinctive feature of Passiflora foetida is its protocarnivorous bracts: the finely divided floral bracts secrete a sticky substance containing digestive enzymes that traps small insects, which appears to reduce predation on flowers and developing fruit. Substances in the leaves are also reported to deter insect herbivores.

Passiflora foetida serves as both a larval host and a nectar source for Gulf fritillary butterflies (Agraulis vanillae) within its native range, with butterflies among its pollinators and seed dispersal aided by birds eating the ripe fruit.

Fully ripe fruits of Passiflora foetida — small, round berries with bluish-white, mildly sweet pulp surrounding numerous black seeds — are eaten raw or used in drinks. Young leaves and shoot tips can also be cooked in soups. Unripe fruit and fresh leaves contain cyanogenic compounds and should not be eaten.

Passiflora foetida has a long history of folk-medicinal use across the tropics. Dried leaves are brewed as a sedative tea in Vietnamese traditional medicine for insomnia, anxiety, itching, and coughs, and elsewhere the plant is used for colds, tuberculosis, intestinal parasites in children, snakebite, and wound healing. Modern studies suggest possible antimicrobial, antiulcer, and antioxidant activity, though clinical evidence is limited.

Beyond food and medicine, Passiflora foetida is notable for its protocarnivorous floral bracts, which trap insects in sticky glandular hairs and may digest them, providing some protection to flowers and fruit. Compounds in the leaves also act as natural insect-feeding deterrents, and the plant is occasionally grown as an ornamental for its showy flowers and unusual "mossy" bracts.