Robust, emergent monoecious aquatic perennial herb to 4 m high. Rhizomes to c. 20 mm diam. Stems to 20 mm diam. Leaves with blade to 2 m long, to 30 mm wide. Upper leaves with sheath of the 2-4 uppermost leaves usually distinctly auriculate. Inflorescence with male and female spikes separated by 0-5 cm. Mature female spikes 8-30 cm long, 10-40 mm diam., chestnut to brown; floral bracts few or apparently absent, narrow-spathulate (usually 3 or 4 cells across); stigmas narrow-obovate, acuminate, markedly concave transversely, not fleshy. Male spike 10-30 cm long, 5-15 mm diam.; pollen shed as single grains.

Astringent, diuretic, emmenagogue, galactogogue and haemostatic (pollen); anticoagulant and haemostatic (dried pollen)

Plants For A Future

The pollen is used internally in the treatment of kidney stones, haemorrhage, painful menstruation, abnormal uterine bleeding, post-partum pains, abscesses and cancer of the lymphatic system and externally in the treatment of tapeworms, diarrhoea and injuries.

Should not be prescribed for pregnant women.