Nuphar japonicum
At a glance
- Lifecycle
- Perennial (hardy)
- Exposure
- Full sun
- Frost limit
- −23.3 °C
Cultivation
A water plant requiring a rich soil and a sunny position. It is best if grown in still water that is up to 75cm deep but it also tolerates slow moving water.
Propagation
Seed - sow as soon as it is ripe in a greenhouse in pots submerged under 25mm of water. Prick out into individual pots as soon as the first true leaf appears and grow them on in water in a greenhouse for at least two years before planting them out in late spring. The seed is collected by wrapping the developing seed head in a muslin bag to avoid the seed being lost. Harvest it 10 days after it sinks below the soil surface or as soon as it reappears. Division in May. Each portion must have at least one eye. Submerge in pots in shallow water until established.
Edible uses
Root - cooked. The root probably needs to be steeped in water before use in order to remove a bitter flavour[K]. Seed. No more details are given but the seed is probably rich in starch and can be ground into a powder then used as a thickener in soups etc[K].
Medicinal uses
Digestive, women's complaints.
Habitat
Ponds, lakes and shallow streams throughout Japan.
Native range
E. Asia - Japan.
Scientific synonyms Nuphar japonica