This type of periwinkle plant contains vinca alkaloids which may cause illness and require the attention of the veterinarian. (wagwalking.com)
Each summer the flower boxes are filled with easy to grow annuals such as geraniums, petunias, creeping jenny, and vinca vine. (3littlegreenwoods.com)
Although there are approximately 30 varieties of the periwinkle plant, the Madagascar periwinkle is the type of periwinkle that contains vinca alkaloids. (wagwalking.com)