Submerged perennial freshwater <5.5m high depending on habitat. Bottom-rooting, stout rhizomes, forms dense beds. Light green leaves, long, flat ribbon-like at regular intervals along rhizomes. Inconspicuous flowers at end of a long spiral stem. Size of plant depends on habitat.
Please note Vallisneria spiralis var. tortifolia is not banned from sale. This plant has twisted leaves rather than the straight leaves of V.spiralis.
Static or flowing freshwater systems <9m deep. Tolerates low salinity. Grows fastest in water temperatures of 25°
Male plants only in NZ, no viable seeds. Spread locally by rhizomes. Intentional planting into new water bodies.
Dense beds of vegetation block dams & waterways impeding drainage, disrupting recreational activities, choking hydro turbines. Out-competes native species.
Virtually impossible to eliminate. Only treat if necessary, interference often makes problem worse. Regular follow up required.
1. Control small infestations using divers to hand-pull plants
Caution: when using any herbicide or pesticide PLEASE READ THE LABEL THOROUGHLY to ensure that all instructions and safety requirements are followed.