The pasture grass hymenachne is notorious as the plant that made its way onto Australia's list of 20 worst weeds (Weeds of National Significance) only 11 years after it was released onto the market as a pasture grass in Queensland.
 
Hymenachne is a giant aquatic grass still grown in dams in northern Australia as a source of dry season feed for cattle.
 
It is readily transported by water, birds or people into rivers and lagoons, where it forms dense infestations, sometimes many hectares in area. Open lagoons decorated with waterlilies, providing habitat for ducks and grebes, are converted into thickets of dense grass. Hymenachne also invades irrigation channels on sugar cane farms.
 
See the article on the Hymenachne Management Strategy in Feral Herald 1:10, August 2005.