Vinca difformis
Vinca herbacea
Vinca major
Vinca minor

Periwinkle (Vinca spp.) is a genus of four species of evergreen subshrubs in the family Apocynaceae, native to Europe, northwest Africa and southwest Asia. They have slender trailing stems 1-2 m long but not growing more than 20-40 cm above ground; the stems frequently take root where they touch the ground, enabling the plant to spread widely. The leaves are opposite, simple broad lanceolate to ovate, 1-9 cm long and 0.5-6 cm broad.

The flowers, produced through most of the year, are salverform (like those of Phlox), simple, 2.5-7 cm broad, with five usually violet (occasionally white) petals joined together at the base to form a tube.

Two species, the Small Periwinkle V. minor and the Large Periwinkle V. major, are very popular plants in gardens, grown for dense evergreen ground cover and their delicate violet flowers.

Pharmacological significance

Periwinkles contain vinca alkaloids that are anti-mitotic and anti-microtubule agents. They are nowadays produced synthetically and used as drugs in cancer therapy and as immunosuppressive drugs. These compounds are vinblastine , vincristine, vindesine and vinorelbine .