The Orange Day Lily is considered old-fashioned, and is now rarely offered by the horticulture industry. In its place are new hybrid Day Lilies that vary in the height of their foliage, color of their flowers, and length of their blooming period. The Orange Day Lily has been in cultivation for a long time, and it often outlasts the buildings that surround it and their inhabitants. In addition to being long-lived and persistent, this hybrid species is able to naturalize in the wild because the foliage is tall enough to compete for sunlight with other species of plants. The only other species of Day Lily that one may encounter in the wild, Hemerocallis lilio-asphodelus (Yellow Day Lily), has a similar appearance, except that its flowers are yellow. The Lilium spp. (true Lilies) superficially resemble the Day Lilies, except that they have corms rather than fleshy roots, flowering stalks with true leaves, and flowers that last longer than a single day.