The genus Hemerocallis is native to Asia, and the orange daylily, H. fulva, grows wild from the Caucasus through the Himalaya to China, Japan and Korea. Most cultivated orange daylilies are sterile triploids that rarely set seed and spread by underground stolons and offsets. Plants can form dense stands that shade out native plants. VASCAN lists the species as introduced in Quebec.
The name Hemerocallis comes from Greek for beautiful for a day, and fulva is Latin for reddish yellow. Orange daylily has been cultivated in Europe since at least the 16th century and later escaped from gardens across much of the United States and parts of Canada.