Description from Flora of China
Nymphozanthus Richard, nom. rej.
Herbs perennial. Rhizomes repent, branched. Leaves dimorphic, either floating with thick leathery blades and long petioles or submersed with thin, papery blades and short petioles; leaf blade ovate to elliptic, venation primarily pinnate, base cordate, margin entire, not peltate. Flowers hypogynous, emergent, perianth ± upright. Sepals (4--)5(--7), yellow or orange, petaloid, oblong to obovate, persistent. Petals numerous, yellow, small, stamenlike. Stamens nearly as long as sepals, inserted at base of ovary; filament strap-like; anthers yellow, connective unappendaged. Carpels completely united. Style absent. Stigma sessile and radiate on flattened stigmatic disc, lacking marginal appendages. Fruit ovoid to urceolate, irregularly dehiscent. Seeds smooth, not arillate.
About ten species: widespread in N temperate regions; two species in China.
(Authors: Fu Dezhi; Donald Padgett)