Erect perennial aquatic, up to 3m tall. Stems arising from thick underground rhizomes. Wide, flat, and stiff sheathing leaves, D shaped on cross section. Leaves are straight in the bottom half but twisted and spiral in the top, pale-greyish-green. Flowers early summer. Dark brown-black erect sausage shaped flower spikes and fruit.
Shallow sheltered waterbodies.
Seed dispersed by wind, water, animals, humans or machinery. Vegetative reproduction also possible.
Forms dense thickets, displacing native vegetation. Could potentially hybridise with native raupo (Typha orientalis).
1. Report it immediately to the Auckland Council Biosecurity team, who will arrange for its control at their expense.
2. Dig up rhizomes remove all material from pond.
3. Spray larger terrestrial infestations (5-7L glyphosate/ha + 200ml penetrant/100L).
4. Spray larger aquatic infestations (5-7L glyphosate/ha/100L, use glyphosate formulation approved for use over water).
Caution: when using any herbicide or pesticide PLEASE READ THE LABEL THOROUGHLY to ensure that all instructions and safety requirements are followed.