Hunting a rare plant in Kakadu

Dave Wilson examining a stand of native water hyacinth at Kakadu, photo by Cory Young

Scientists from CSIRO have been hard at work in Kakadu, collecting rare plant specimens.

They were searching for the elusive native water hyacinth, Monochoria hastata. Kakadu is one of only two places in Australia where this native plant is known to grow, and finding it has taken a bit of leg work!

The CSIRO researchers need samples of the plant as part of a project to control an invasive weed – the exotic water hyacinth, Eichornia crassipes. It’s an ornamental plant from overseas that’s taken hold in eastern Australia, particularly in the Richmond Tweed area. It has just been recognised as a Weed of National Significance. It takes over waterways and it’s very hard to shift, so scientists are investigating biocontrol options.

CSIRO has found a bug that eats the exotic water hyacinth, but before they can release it in Australia they need to be sure that it doesn’t target similar native species (no one wants another biocontrol case like the cane toad!).

That’s where Kakadu comes in - the native water hyacinth from Kakadu will be tested to make sure it’s safe from the appetites of the new bug.

Native water hyacinth

CSIRO got a permit to collect the plant specimens at Kakadu, and ranger Buck Salau expertly guided them to Benbunga Swamp, where he knew the plant could be seen. They found around 5,000 of the plants, so the 38 seedlings they collected haven’t made a dent in the population.

It’s great to know such a rare plant is thriving in Kakadu, and our research partnerships are as strong as ever.

Anne, Kakadu National Park