A family of 4 genera and about 30 species, of disjunct distribution in north temperate and subarctic areas, and in the Guayana Shield and northern Andes areas of n. South America. There is controversy about the circumscription of the genera; Azuma & Tobe (2011) have clarified the phylogeny and generic subscriptions in the family. Some have believed that Tofieldia, Triantha, and Pleea should be treated together in a broadly circumscribed Tofieldia (Utech 1978, Zomlefer 1997c); others that all three should be treated separately (Ambrose 1980; Packer 1993; Cruden 1991). Packer in FNA (2002a) has recently recognized Triantha, Pleea, and Tofieldia as separate genera, a conclusion followed here in part because of the ancient, relictual nature of these units, and additionally supported by the molecular analysis of Azuma & Tobe (2011). Reveal & Zomlefer (1998) place the Tofieldiaceae in the monotypic order Tofieldiales, only distantly related to the Liliaceae. Tamura in Kubitzki (1998a) treats this group as subfamily Tofieldioideae of the Nartheciaceae; this treatment is not tenable following more recent research.