With its alien-looking flowers, egg-shaped fruit and wandering tendrils, passionflower is one of the most unusual plants you'll ever come across in the U.S. Known botanically as Passiflora incarnata, passionflower is native to the southeast and mid-south regions of the United States. This climbing vine that so entranced Spanish missionaries in the 1600s can grow 30 feet long, inhabiting fence rows, woodlands and backyards alike.

Traditional Medical Uses for Passionflower

Native Americans crushed passionflower's lobed leaves and applied them directly to the skin to ease bruises, cuts and other wounds. Infusions made from the leaves were used to treat ear infections, strengthen the blood and relieve stress. And until 1978, when the FDA pulled its support of the herb, it was included in many over-the-counter sleep aids.

Passionflower Today

In 1978, the FDA re-classified passionflower as a Class II herb, citing a lack of substantiated evidence that passionflower was effective as a sedative. But passionflower is still widely used in Europe where passionflower extract is frequently combined with extracts of other natural sedatives like valerian, chamomile and lemon balm.

Today's herbalists use passionflower as a digestive aid, as a stress-reducer and as an insomnia treatment. Passionflower can be used fresh but it's more frequently dried for use in pills, teas and extractions like tinctures and infusions.

Current Research

Though passionflower is widely used, it's not been widely studied. But the few studies that have been done are encouraging. A European study of people with generalized anxiety disorder found that passionflower was as effective as prescription medications as relieving anxiety.

And another study looking at treatments for congestive heart failure found that an extract of hawthorn and passionflower improved symptoms like shortness of breath.

Other unproven uses for passionflower include opiate detoxification, ADHD and seizures.