Periwinkle, or vinca, has been used for its sedative properties to calm the nerves and to stop bleeding such as from hemorrhoids or heavy menstrual periods. A tea can be made from the dried leaves. Periwinkle is a low growing perennial shrub with vine like properties, tough leaves and stems, and periwinkle blue flowers. Yes, the name also describes a shade of blue. This plant can become invasive as it can smother out other plants. I know because I had some in my yard and it was like the creeping blob, taking over more and more yard. I finally got rid of it but it was a lot of work. “Perhaps the most intriguing dietary supplement derived from periwinkle is vinpocetine, which is made from an alkaloid chemical in lesser periwinkle called vincamine. Several studies of vinpocetine suggest that it may improve brain function and memory, particularly in people affected by diseases that decrease mental capacity such as Alzheimer’s disease or dementia .” (This quote is from encyclopedia.com) There is a tall growing Madagascar periwinkle that comes in shades of pink, red and white. This is usually grown for its lovely flowers as an annual.