Curly WaterweedInvasive Species IdentificationCurly waterweed, AKA African Curly Waterweed, grows underwater and is attached to the bottom by roots. Its leaves are arranged in spirals along the stem and are very curled. The stem is hollow and brittle, and can grow up to 6.5m long.The leaves are green, with a yellowish tinge. In summer, the weed produces small flowers with 3 white or pink petals. Curly waterweed can be mistaken for Nuttall´s or Canadian waterweed but these have their leaves arranged in a circle (whorl) around the stem.The leaves form a cluster at the top of the stem, giving the plant a distinctive look.ThreatCan form dense mats up to 2 – 3m thick.Curly waterweed is very difficult to control, and its ability to form new plants from small fragments means that it is easily spread to new locations.All aquatic weeds present the following threats:They form thick, dense mats that prevent light from reaching native plants and can be mistaken for solid ground by children and animals.The thick mats also prevent oxygen from entering the water, drastically reducing oxygen levels, which may kill fish and other aquatic life.A large infestation greatly reduces access for recreational water activities.Mats of aquatic weeds often result in a bad smell and reduced visibility in the water.Dense mats can reduce the flow of water and increase the risk of flooding.ActionCheck, clean and disinfect all equipment, boots, wheels and anything that made contact with the water. This will ensure you don’t carry fragments to other possible habitats.The control of large infestations of aquatic weeds will require the services of an appropriately certified invasive species control company. If you encounter curly waterweed please enter the details into our log.