Perennial free-floating, mat-forming, stoloniferous aquatic herb. Roots are dark, feathery and < 2.5 m long. Leaves are bright green, rounded and shiny, with bulbous bladder-like leafstalks when young. Flowers are pale purple with darker purple/blue markings and a yellow spot and are borne in clusters above the leaves in mid-summer – early autumn.
To help protect our environment:
Still and slow-flowing water bodies, lakes, rivers, ponds, streams.
Seeds dispersed by water and possibly waterfowl and other animals. Vegetative spread from stolons and budding, dispersed by water and wind. Human-mediated dispersal through deliberate plantings and movement of contaminated boats and equipment.
Forms dense mats, outcompeting native plants and altering habitat structure. Clogs waterways, impeding drainage and recreational activities.
Do not attempt to undertake control of this species. The Ministry of Primary Industries will carry out the control of this species.
CAUTION: When using any herbicide or pesticide please read the label thoroughly to ensure that all instructions and safety requirements are followed.