Native to southeastern parts of the Americas, passionflower is now grown throughout Europe. It is a perennial climbing vine with herbaceous shoots and a sturdy woody stem that grows to a length of nearly 10 meters (about 32 feet). Each flower has 5 white petals and 5 sepals that vary in color from magenta to blue. The passionflower's ripe fruit is an egg-shaped berry that may be yellow or purple and some but not all fruit is edible. The pharmacological activity of Passiflora is attributed primarily to the alkaloids and flavonoids present in the plant. It contains harmala alkaloids, which inhibit monoamine oxidase. Monoamine oxidase is involved in removing the neurotransmitters norepinephrine, serotonin and dopamine from the brain. MAOIs prevent this from happening, which makes more of these brain chemicals available. This is thought to boost mood by improving brain cell communication. This may account for part of Passionflower’s pharmacologic effects. Scientists also believe passionflower works by increasing levels of a chemical called gamma aminobutyric acid (GABA) in the brain. GABA lowers the activity of some brain cells, making you feel more relaxed.