Current alert weeds: how to report

The alert weeds below have been detected in the Northern Territory (NT) and continue to present a major threat.

If you think you have seen any of the weeds on this page in the NT contact the Weed Management Branch immediately.

Do not try to dispose or control any of these weeds without expert help.

These weeds are targeted for complete eradication by Weed Management Branch with the assistance of landholders.

Current alert weeds are:

Sagittaria

Sagittaria is an aquatic weed that already affects waterways across Australia.

It is considered a Weed of National Significance because it is highly invasive, has the potential to spread and can have economic and environmental impacts. It is not currently known to be naturalised in the Northern Territory.

Incorrectly labelled sagittaria plants were sold to the public by Bunnings Darwin, Bunnings Palmerston and Mitre 10 Katherine in September 2016. 

The sagittaria was incorrectly labelled as Melon Sword (Echinodorus osiris).  Customer receipts may also list the sale as Tibouchina coolbaby.

Through a media campaign and public recall, the Weed Management Branch has now identified sagittaria growing in a pond on a Howard Springs property. These plants are believed to have been growing there for about 10 years. The Weed Management Branch is concerned that sagittaria may have spread from the site into adjoining wetlands and is currently conducting surveys as part of an emergency response.

If you think you have seen a plant that looks like sagittaria, have it growing on your property or have recently bought a plant that resembles sagittaria, please contact the Weed Management Branch on (08) 8999 4567.  Do not attempt to control or dispose of any suspect plants yhourself.

If you have planted what you now believe is sagittaria into a water feature or pond, leave it where it is and contact the Weed Management Branch for help.

Read sagittaria for information on how to identify this weed and its potential impact.

Sagittaria 

Pond apple

Pond apple was found in Bees Creek in 2010 and in the Darwin suburb of Millner in 2012. 

The largest finding was in Howard Springs in 2012, with more than 100 plants growing on many properties. 

These properties back onto a drainage line that flows into the Howard River catchment.

Read more on pond apple for information on how to identify this weed and its potential impact.

Pond apple - flower 

Rubber vine

This does not include the ornamental variety. 

A single rubber vine plant was found in Nightcliff in November 2012. There has only been one other known occurrence of rubber vine in the NT which was on the Barkly Tablelands in 2011. 

Ornamental rubber vine has been deliberately planted in some urban gardens. This species should also be destroyed as it has been known to cross breed with rubber vine.

Read more on rubber vine for information on how you can identify this weed and its potential impact.

Rubber vine - flower 

Cabomba

Cabomba was found in the Darwin River area in 2004 along an 11km stretch. Control efforts have reduced this infestation to a 1km stretch limited to Lok Landji Billabong in the lower Darwin River. 

A quarantine order (163.0 kb) is in place for this area and you are not allowed in. 

Given historical use in the aquarium trade, positive cabomba identifications have been made in urban ponds and fish tanks. You must report suspected cabomba in these areas.

Read more on cabomba for information on how you can to identify this weed and its potential impact.

Cabomba - flower 

Water hyacinth

Water hyacinth has been eradicated from the NT, but two positive identifications were made in April 2011 in urban ponds.

Read more on water hyacinth for information on how to identify this weed and its potential impact.

Water hyacinth - flower 

Parthenium

Parthenium weed was found in April 2010 at the Tennant Creek stockyards. The four affected holding pens are padlocked. 

The area is still considered an active parthenium site with quarantine measures still in place. NT Government staff have been monitoring the site regularly. 

There have been no signs of parthenium in or surrounding this site. There are no other known active infestation sites in the NT.

Read more on parthenium for information on how to identify this weed and its potential impact.

Parthenium - flowers 

Water mimosa

Water mimosa was first found in a dam in the Darwin Rural area in 2001 and then in the town lagoon at Nhulunbuy in March 2012. 

Read more on water mimosa for information on how to identify this weed and its potential impact.

Water mimosa - stems and branches

Last updated: 28 November 2017