Periwinkle is native to Europe and is mainly a ground-hugging evergreen shrub reaching about eighteen inches in height. It has rooting stems, shiny elliptical leaves, and five-petaled violet-blue flowers. It often grows wild along roadsides and woodland borders or cultivated as a garden ornamental. The leaves are gathered in spring.
Periwinkle was listed in the 2nd century CE Roman Herbarium by Apuleius. In it, he stated that the herb was used against “devil sickness and demoniacal possessions and against snakes and wild beasts”. He also described the entire ritual necessary for harvesting the herb.