NQ DRY TROPICS WEED FREE pg . 79
WATER HYACINTH
Eichhornia crassipes
DESCRIPTION
This floating perennial water weed has a black root system and erect stems that can reach up to 1 metre long when the plant is fully matured .
Leaves are dark green rounded and waxy up to 5 centimetres wide . Leaf stalks are 5 to 20 centimetres long and are swollen into spongy , bulbous dense clusters .
Flowers are light purple with a darker bluish-purple and yellow centre . They are up to 4 centimetres long on dense spikes that are 50 centimetres long , with 3 to 15 flowers per spike . It flowers during summer and autumn .
Fruit are 3 celled capsules with small seeds that are viable for 15 years .
Habitat it prefers water with high nutrient content such as areas contaminated by sewage plant outflow and washings from stockyards .
Weed characteristics it invades creeks , rivers and dams as dense mats spread across water surfaces and infestations can double in size every week under ideal conditions . It destroys native habitats , depletes water bodies of oxygen , increases water loss and provides a breeding ground for mosquitoes . Stock may have difficulty accessing drinking water .
Dispersal it grows from seed and through vegetative reproduction .
BIOSECURITY MATTER
Restricted . This species is Category 3 Restricted matter under Queensland Legislation . This species is also listed a Weed of National Significance ( WONS )
HOW TO ACT
Prevention is the best control method . Early detection and rapid response will provide the best chance of control . Control of nutrient inputs into waterways will reduce rate of infestation . Integrated control combining mechanical , biological and chemical methods with long term monitoring and follow up required . Hand removal of small infestations is recommended , with ongoing monitoring and follow up required due to persistent seed viability . Biological control agent is effective in reducing plant vigour but does not provide complete control . Apply herbicide strictly as per label recommendations .
WATER WEEDS WATER HYACINTH