Catharanthus roseus is known as the common or Madagascar periwinkle, though its name and classification may be contradictory in some literature because this plant was formerly classified as the species Vinca rosea, Lochnera rosea and Ammocallis rosea. Furthermore, lesser periwinkle (Vinca minor) may also be called common periwinkle. Both species are also known as myrtle.

In any case, Catharanthus roseus is a perennial, evergreen herb and was originally native to the island of Madagascar. It has been widely cultivated for hundreds of years and can now be found growing wild in most warm regions of the world, including the Southern U.S. The plants grow one or two feet high, have glossy, dark green leaves (1-2 inches long) and flowers all summer long. The blooms of the natural wild plants are a pale pink with a purple "eye" in their centers, but horticulturists have developed varieties with colors ranging from white to hot pink to purple. Like dannye says, they're extremely pretty.

The plant has historically been used to treat a wide assortment of diseases. It was used as a folk remedy for diabetes in Europe for centuries. In India, juice from the leaves was used to treat wasp stings. In Hawaii, the plant was boiled to make a poultice to stop bleeding. In China, it was used as an astringent, diuretic and cough remedy. In Central and South America, it was used as a homemade cold remedy to ease lung congestion and inflammation and sore throats. Throughout the Caribbean, an extract from the flowers was used to make a solution to treat eye irritation and infections.

It also had a reputation as a magic plant; Europeans thought it could ward off evil spirits, and the French referred to it as "violet of the sorcerers."

Western researchers finally noticed the plant in the 1950's when they learned of a tea Jamaicans were drinking to treat diabetes. They discovered the plant contains a motherlode of useful alkaloids (70 in all at last count). Some, such as catharanthine, leurosine sulphate, lochnerine, tetrahydroalstonine, vindoline and vindolinine lower blood sugar levels (thus easing the symptoms of diabetes). Others lower blood pressure, others act as hemostatics (arrest bleeding) and two others, vincristine and vinblastine, have anticancer properties. Periwinkles also contain the alkaloids reserpine and serpentine, which are powerful tranquilizers.

Because the alkaloids in this plant can have serious side effects such as nausea and hair loss, it is not recommended that people attempt to medicate themselves with periwinkles.


References:

Dobelis, Inge N., ed. 1989. Magic and Medicine of Plants. Pleasantville, NY, Reader's Digest Books.

Heywood, V.H., ed. 1993. Flowering Plants of the World. New York, NY, Oxford University Press.

Simpson, Beryl Brintnall and Molly Conner-Ogorzaly. 1986. Economic Botany: Plants in Our World. New York, NY, McGraw-Hill Publishing Co.