The greater periwinkle

Greater periwinkle (Vinca major)

The greater periwinkle is native to southern Europe from Spain and southern France east to the western Balkans and north-eastern Turkey. It is sometimes grown in gardens and can also be found the Maltese countryside where it has been introduced and become naturalised.

It is a fast growing herbaceous perennial trailing vine with evergreen foliage and pretty blue flowers. The arching stems of the greater periwinkle can reach about 30 cm in height, but they soon fall over and spread indefinitely along the ground. The flowers are produced from early spring to autumn. In many parts of Europe one finds a similar species, the common periwinkle, which is not found in Malta.

Gardeners have developed various cultivars such as the ‘Alba’ which has white flowers, Oxyloba which has deep blue flowes and others which are grown for their variegated foliage.

The two species are well known for their medicinal properties. The periwinkle is known for its astringent, or drying qualities and herbalists used it to treat any health condition with symptoms of excessive flow, from bleeding gums to heavy periods. They have also been used to treat diarrhea, colitis, canker sores and tinnitus, the ringing in the ears that plagues many people.

The modern pharmaceutical industry utilises a number of chemical compounds found in the plants to provide cure for several medical conditions. Vincamine, an alkaloid extracted from the plants, is used as a cerebral stimulant and vasodilator whilst another compound, reserpine, reduces high blood pressure.

Studies are still being carried out on these plants to find new uses for them. Results have shown that there are many potential uses although some are controversial and more studies are needed to determine the effectiveness and safety of the cures being claimed.

A few months ago studies were started in South Africa to study the traditional use of this plant to treat diabetes and pre-diabetic conditions. The periwinkle has been used throughout Europe for centuries as a diabetic treatment, but few studies exist to demonstrate its efficacy in treating this serious condition.

Another controversial use of the greater periwinkle is to treat cancer. This species contains another two powerful chemicals, vincristine and vinblastine which are used in chemotherapy treatments. It is also claimed that as the periwinkle increases blood flow to the brain it can be used to treat Alzeheimer and other memory problems.

A non-contoversial use is in the cottage industry. In parts of Europe the stems of these plants are used to weave baskets.

 This article was published in The Times on 25.03.09.