Cyperaceae: a creeping, robust perennial to 1.25m. Found in brackish water margins. The stems are rough and triangular. The flowers are a tight, terminal cluster of egg-shaped spikelets, flanked by a long, leafy bract, July- Aug. leaves rough and keeled. Locally common round the British coast, but occasionally found in freshwater habitats inland.
The root can be eaten raw or cooked. Rich in starch, it is usually dried and ground into a powder.
The root has astringent and diuretic properties. It is used in the treatment of amenorrhoea, dysmenorrhoea, abdominal pain or tumours for post-partum females, abdominal distension, and indigestion.
The leaves are used in weaving and basketry.
Waterplants must be sown in waterproof plastic trays or similar containers containing a nutritious muddy compost. Fill water up to 1 cm over the top of the compost. Keep the trays at warm temperatures of approximately +22°C. Succeeds in any wet to moisture retentive ground, pond margins and shallow water in full sun or shade. Fully hardy.