Requires a sunny position. A plant of wet habitats, it succeeds in wet soils and in water up to 30cm deep. A very ornamental plant. The flowers have a scent of bitter almonds.

Tuber - cooked. It should be peeled and the rootlets removed. The root can also be dried and ground into a powder, it can then be used as a thickener in soups etc, or be added to cereal flours when making bread. It contains more than 50% starch. Seed. No more details are given, but the seed is very small and fiddly to use.

Seed - best surface-sown in a cold frame as soon as it is ripe, it usually germinates in the spring. The seed quickly loses its vitality if it is not kept moist. When large enough to handle, prick the seedlings out into individual pots and grow them on in a tray of water in the cold frame, planting them out into their permanent positions in early summer. Division in spring. Very easy, larger clumps can be planted direct into their permanent positions. It is best to pot up smaller clumps and grow them on in a cold frame until they are well rooted before planting them out in the summer.

Pond margins, ditches and canals, avoiding shade.