Rhizomes subcylindric, short, thick. Leaf blade entire, pinnately veined, base elongate, stomatal apparatus mostly anomocytic. Inflorescence with 4 involucral bracts. Perianth campanulate, 6-lobed; lobes variable in size, soon deciduous. Ovary 1-loculed; placentas 3, parietal. Fruit a capsule. Seeds oblong, irregularly oblong, ovoid, or semilunar.

Medicinal.

Two species: China, Laos, Thailand, Vietnam; two species (one endemic) in China.