Plantae>Magnoliophyta>Magnoliopsida>Gentianales>Apocynaceae>Vinca major L.
Bigleaf, or Greater Periwinkle is a rampant groundcover that persists and sometimes spreads from cultivation. Fortunately it doesn't seem to spread from seed in North Carolina. The almost cordate (heart-shaped) leaves are much larger and broader than those of the Common Periwinkle (Vinca minor).
Durham, NC 9/11/08.
It works well as a groundcover, taking over and preventing other plants from growing, but is not a good choice for gardeners who may someday be interested in growing wildflowers or other plants besides Periwinkle.