Water hyacinth (Eichhornia crassipes)
Water hyacinth with root detail
Water hyacinth is a Class A (to be eradicated) and Class C (not to be introduced to the Northern Territory) weed in accordance with the NT Weeds Management Act 2001.
- Water Hyacinth Photo Identification Table (pdf 139KB)
- Water Hyacinth Brochure - July 2008 (pdf 127KB)
Water hyacinth is an attractive, floating aquatic weed with dark green rounded leaves. Flowering between October to July, the flowers are light purple with a darker blue or purple and yellow centre. Water hyacinth can reproduce both vegetatively (by producing daughter plants) and through the production of seed. A single plant can produce enough growth to cover 600m2 in one year. Seeds are viable for up to 20 years.
Water hyacinth infestation
Water hyacinth was introduced into Australia in the 1890’s as an ornamental plant for ponds and aquariums. It is usually free-floating, although can become attached to muddy banks. It is an aggressive invader of permanent freshwater bodies and can grow quickly to produce large, dense mates of the water surface. Infestations have been known to double in size in a few weeks and exceed 700 000 hectares.
Water hyacinth is considered a significant threat as it can destroy freshwater wetlands and the native plants and animals which live in them; block waterways and reduce water quality, increase water storage capacity of dams and interfere with irrigation; restrict recreational activities including swimming, fishing and boating; and can provide a suitable habitat for mosquito breeding.
Almost every infestation that has occurred in eastern and southern Australia is a direct result of planting or through the disposal of unwanted plants into watercourses. In the past 24 years, six infestations have been recorded and eradicated in the Northern Territory. There are currently no known established infestations of water hyacinth in the Northern Territory.
Report water hyacinth sightings immediately to the Weed Management Branch on 8999 4567. Weed Management Officers will remove and dispose of plants free of charge.
