Periwinkle or Myrtle
Vinca minor
Although an alien plant, Vinca has established itself throughout the area so much so that we all know what it looks like.
Vinca minor is believed to have originated in southern Europe. It now grows in most mild climates, where it is used commonly as an ornamental ground cover. Its small, dark, shiny leaves stay green all year and its characteristic flowers --usually light blue-purple -- bloom most of the spring and summer.
Some of the chemicals found in plant species related to Vinca minor have been developed into prescription drugs to treat cancer. Vinca minor contains similar chemicals, but the amounts of those and other chemicals in fresh or dried Vinca minor plants vary depending on how the plants are grown, harvested, processed, and stored. The FDA does not recognize Vinca minor as safe. Therefore, its use is not recommended.