Click on images to enlarge
infestation in a waterway (Photo: Sheldon Navie)
infestation on muddy soil (Photo: Sheldon Navie)
submerged habit (Photo: Sheldon Navie)
terrestrial habit (Photo: Sheldon Navie)
stems with roots at their joints (Photo: Sheldon Navie)
submerged leaves (Photo: Sheldon Navie)
emergent leaves (Photo: Sheldon Navie)
close-up of younger emergent leaves (Photo: Sheldon Navie)
Hygrophila polysperma (Roxb.) T. Anderson
Justicia polysperma Roxb.
dwarf hygrophila, East Indian hygro, East Indian hygrophila, East Indian swampweed, green hygro, hygro, hygrophila, Indian swamp weed, Indian swampweed, Indian water star, Miramar weed, oriental ludwigia
Native to the Indian Sub-continent (i.e. Bangladesh, Bhutan, India and Nepal) and south-eastern Asia (i.e. Cambodia, Laos, Myanmar, Thailand and Vietnam).
Currently only naturalised at a few locations in south-eastern Queensland and north-eastern New South Wales.
Also naturalised overseas in eastern USA (i.e. Florida, Texas and Virginia).
East Indian hygrophila (Hygrophila polysperma) is regarded as an emerging environmental weed in Queensland and New South Wales. This species was first collected in Australia in August 2005 in the Caboolture River north of Brisbane. It was growing along the riverbank and in the water, both as a submerged aquatic and terrestrial plant. East Indian hygrophila (Hygrophila polysperma) is thought to have escaped cultivation as an aquarium plant and has since been found along the Tweed River and Clarence River in coastal northern New South Wales and along Enoggera Creek in suburban Brisbane.
This species has the potential to become a serious weed of freshwater lakes, ponds and dams in eastern Australia. It prefers flowing water in warmer environments, but may also be found in slow moving waters and lakes. East Indian hygrophila (Hygrophila polysperma) is fast growing invasive plant that out-competes native aquatic plants. It can occupy the entire water column and also creates problems as an emergent plant along the margins of waterbodies.
East Indian hygrophila (Hygrophila polysperma) has replaced hydrilla (Hydrilla verticillata) as the major aquatic weed in some parts of Florida, and is considered by the state's Exotic Pest Plant Council to be one of the most invasive non-indigenous aquatic plants in this part of the USA. It forms dense stands and floating mats of vegetation in waterways, canals and drainage ditches, which obstruct water flow and displace native vegetation. Its ability to form a dense canopy at the water-air interface is of particular concern, because this enables it to shade out all other submerged plants.
Fact sheets are available from Department of Employment, Economic Development and Innovation (DEEDI) service centres and our Customer Service Centre (telephone 13 25 23). Check our website at www.biosecurity.qld.gov.au to ensure you have the latest version of this fact sheet. The control methods referred to in this fact sheet should be used in accordance with the restrictions (federal and state legislation, and local government laws) directly or indirectly related to each control method. These restrictions may prevent the use of one or more of the methods referred to, depending on individual circumstances. While every care is taken to ensure the accuracy of this information, DEEDI does not invite reliance upon it, nor accept responsibility for any loss or damage caused by actions based on it.
Copyright © 2016. All rights reserved. Identic Pty Ltd. Special edition of Environmental Weeds of Australia for Biosecurity Queensland.
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