Jefferson listed "Periwinkle" among "Hardy perennial flowers" for planting in a note dated September 30, 1771, and again as "Perywinkle" in 1794 among a list of "Objects for the garden this year." A native of Europe and Western Asia, Periwinkle is a hardy trailing plant ideally suited for ground cover in shady areas. Its small, five-petaled flowers are typically shaded purple or blue, but sometime show in white.