Daylilies are flowering perennials native to China, Korea and Japan. There are over 60,000 registered daylily cultivars worldwide, but the best-known is the so-called tawny' or orange daylily. The tawny daylily goes by other names: ditch lily, tiger lily, tiger daylily, common daylily. In some parts of the United States such as Wisconsin, the tawny daylily is considered an invasive species. Daylilies grow in clumps that can be separated to grow plants in new locations.