PASSIFLORACEAE

The Passifloraceae or passionflower family comprises approximately 700+ species of tropical climbers, shrubs or trees. The predominant genus is Passiflora, with some 500+ species of neotropical vines. Passiflora is so named because the flower (protruding stigma) resembles Jesus’s crucifixion. Many species are cultivated as ornamental fruits such as the passion fruit (P. edulis) and granadilla (P. ligularis & P. quadrangularis). Passiflora are frequently planted as ornamental flowers.

Passiflora elaborate two groups of toxins, namely, the harmala alkaloids, and cyanogenic glycosides. Harmala alkaloids produce anti-depressant and mildly euphoric activity. They inhibit the brain from breaking down 'happy hormones' like dopamine, serotonin and noradrenaline. However, when harmala alkaloids are ingested together with tyramine-rich food (e.g., cheese), they can cause fatal side effects. The leaves of Passiflora also contain cyanogenic glycosides, which release cyanide when the plant tissue is injured. Cyanide prevents the body from using energy, victims suffocate to death from the inside out. The toxicity of Passifloraceae has driven the evolution Heleconid butterflies. Other lesser known Passifloraceae such as Adenia spp. contain highly toxic toxalbumin, which is similar in action to abrin and ricin. 
 

The stinking passionflower (Passiflora foetida) is rich in cyanogenic glycosides.

The sticky bract of Passiflora foetida traps and kills insects. It has glands that secrete digestive enzymes, but whether or not P. foetida feeds on insect remains debatable. This makes P. foetida one of the few examples of protocarnivorous plant.

The red passionflower (Passiflora coccinea) is commonly planted as an ornamental flower.

Grape-leaf passionflower (Passiflora vitifolia).

Purple passionflower (Passiflora incarnata).

Lady Margret's passionflower, horticulture cultivar between P. coccinea X P. incarnata.