Periwinkle is the name of about a dozen species of small, evergreen flowering shrubs and ground-cover plants. They are best known for the intense blue or purple-blue color of their flowers. Periwinkles are native to Europe, Africa, and Asia, and have been introduced to many other countries as ornamental plants.
The greater, or big leaf, periwinkle and common, or lesser, periwinkle are low, spreading undershrubs (shrubs that grow under bushes). They have dark-green, spear-shaped, leathery leaves. People usually plant them in shady positions in parks and gardens. The Madagascar periwinkle is a tropical species with rose pink flowers. An extract from it stops the growth of certain types of human tumors and is used as an anticancer drug.
