Plants with young vegetative parts heavily mucilaginous. Leaves all floating, long petiolate; leaf blade broadly elliptic, venation radiate, margin entire. Flowers anemophilous, usually long pedunculate; perianth not showy. Sepals linear-oblong to narrowly ovate. Petals narrowly oblong, lacking basal auricles. Stamens 12--36(--51), opposite both sepals and petals. Pistils 6--18; ovules (1--)2; stigmas linear-decurrent. Fruit slightly to strongly fusiform; seeds ovoid, lacking tubercles.
Herbs , young vegetative parts heavily coated with mucilage. Leaves floating; petiole long. Leaf blade elliptic. Flowers: sepals 3, not petaloid, linear-oblong to narrowly ovate; petals 3, linear-oblong, lacking auricles, base not clawed; stamens 18-36(-51), opposite both sepals and petals; pistils 4-18, simple, 1-locular; ovules (1-)2; stigma linear-decurrent. Fruits slightly to strongly fusiform. Seeds ovoid, tubercles absent. x = 40.
"Sep somewhat petaloid, colored within; stamens 12–18, or reputedly to 36; filaments of 2 lengths; anthers introrse, pistils 4–8; submerged parts covered with a mucilaginous jelly; lvs alternate, mostly crowded near the summit, long-petioled, with floating, centrally peltate blade. Monospecific"
Floating leaves peltate; submerged leaves absent
Sepals and petals persistent in fruit
Testa with cells of outer layer very characteristically elongated radially.
|Water-shield [for Christoph Brasen, 1774, Moravian missionary and plant collector in Greenland and Labrador]|