Description from Flora of China
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.
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).
About 20 species: mainly in subarctic, temperate, and subtropical regions of the N hemisphere; three species (two endemic) in China.
(Authors: Chen Xinqi (陈心启 Chen Sing-chi); Minoru N. Tamura)