A family of 1 genus, Hemerocallis, and 16 species of rhizomatous or tuberous rooted herbs from north Asian temperate regions, particularly Japan. [Watson, L., and Dallwitz, M.J. 1992 onwards. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 25th November 2009. http://delta-intkey.com]. Phormiaceae is sometimes included in the family. Previously included in Liliaceae.