Herbs perennial, with a short, ascending rhizome. Leaves basal or nearly so, 2-ranked, basally equitant, sword-shaped, laterally flattened. Scape erect, slender, apically with a many-flowered raceme or rarely a spike. Flowers bisexual, arising from axils of bracts, small, often subtended by 1 cupular or rarely 3 nearly free bracteoles. Perianth segments 6, free or basally connate, persistent. Stamens 6, often free, sometimes connate at base or inserted at base of perianth segments; anthers ovate, basifixed or subdorsifixed, introrse to latrorse. Ovary superior, usually ovoid, 3-lobed apically, stipitate or sessile; ovules numerous; septal nectaries often present. Styles 3, rather short, with introrse stigmas. Fruit a septicidal capsule, 3-loculed, sometimes folliclelike due to very deep clefts. Seeds small, usually linear to oblong.
About 20 species: mainly in subarctic, temperate, and subtropical regions of the N hemisphere; three species (two endemic) in China.
Although Tamura (in Kubitzki, Fam. Gen. Vasc. Pl. 3: 389. 1998) placed Tofieldia in the Nartheciaceae, Wu Zhengyi (editor’s note) believes it should be treated in the segregate family Tofieldiaceae, as was done by Takhtajan (Diversity Classific. Fl. Pl. 478. 1997).
