Propagation
Divide the clump (rhizome) during spring and take care as the rhizomes are fragile and resent disturbance. Place in shallow water till shoots appear then gradually place in deeper water.
Sow fresh seed during spring. 

Culture
Over winter in cold climates lift the rhizomes and place in a frost-free position although the rhizomes will tolerate frozen water and soils if they are planted deeply.

Botanic information
Leaf: The glaucous green leaves are concave-orbicular with radiating veins that are prominent on the underside and undulating entire margins. The texture is waxy with the upper surface revealing a silvery colour as water runs across it. It is held above the water on a long petiole.

Flower: The crateriform flowers are pink to white with a yellow centre and are held above the foliage on a stiff spiny pedicle and appear during summer.  

Fruit: The nut is ellipsoid (pepper-pot shape) and is used as a decorative addition to flower arrangements. The seeds have a very long viability period up to 2,000 years but the plant is normally reproduced vegetatively to maintain true to type.