Description from Flora of China
Herbs perennial or rarely annual, aquatic. Stems rhizomatous; rhizomes erect or repent, branched or unbranched. Leaves arising from rhizome, simple, alternate, floating, emersed, or submersed, long petiolate but short petiolate on submersed vernal ones; leaf blade undivided, usually with a basal sinus, often peltate. Flowers solitary, axillary, long pedunculate, bisexual, hypogynous to epigynous, actinomorphic, entomophilous, mostly emergent. Sepals 4--7, usually green, occasionally petaloid. Petals numerous (rarely absent), distinct, usually showy, often transitional to stamens. Stamens numerous; anthers introrse, dehiscent by longitudinal slits; connective sometimes appendaged. Pistil 1, compound; carpels 5--many, partially or completely united, surrounding a sometimes projecting floral axis. Ovary multilocular; placentation laminar; ovules numerous. Styles absent or modified into abaxially projecting carpellary appendages. Stigmas radiate on distal surface, often disclike. Fruit berrylike, many seeded, irregularly dehiscent. Seeds mostly arillate; endosperm little, perisperm abundant; embryo small; cotyledons 2, fleshy.
Kuan Ke-chien. 1979. Nymphaeaceae subfam. Nymphaeoideae. Fl. Reipubl. Popularis Sin. 27: 6–15.
Six genera and ca. 70 species: widespread in temperate and tropical regions; three genera and eight species in China.
(Authors: Fu Dezhi; John H. Wiersema)