Kidneyleaf mudplantain

• Aquatic annual or perennial 20–50cm tall.
• Stems are submerged or floating and root at any node when in soil.
• Flowering stems are 1–9cm long.
• Leaves are 5cm long, 3cm wide, rounded or kidney-shaped, arranged alternately along stems.
• Flowers are very small, white to pale blue, 3–6.5mm, open only for 3 hours after sunrise.
• Fruit is capsule with 8–14 seeds.
• Seeds are winged, 0.5–0.9mm long, 0.3–0.5mm wide.

• Prefers open, sunny sites with nutrient-rich soil and water less than 15cm deep.
• Found in roadside ditches, on edges of freshwater streams, rivers and ponds, and on freshwater tidal mudflats.

• Naturalised populations found in coastal South East Queensland.

• Seed banks can exist in soil for many years.

Environmental

• Forms dense mats that smother native aquatic plants.

Economic

• Serious weed of flooded rice fields overseas.
• Provides good habitat for mosquitoes.

• Fragments of stems can spread by water and wind.

• Find out how farmers can prevent weed spread.
• Find out how gardeners and outdoor enthusiasts can prevent weed spread.

Physical control

• Plants in ponds or small dams can be removed by physical and mechanical means, taking care to remove all root mass. Follow-up will be required.

Herbicide control

• No herbicide is currently registered in Queensland; however, an off-label use permit (Permit No. PER14122) allows minor use of a herbicide product to control kidneyleaf mudplantain by persons who are employees of Queensland local and state governments and persons under their direction who are trained and experienced in the use of agricultural herbicides.

• Kidneyleaf mudplantain is not a prohibited or restricted invasive plant under the Biosecurity Act 2014. However, by law, everyone has a general biosecurity obligation (GBO) to take reasonable and practical steps to minimise the risks associated with invasive plants under their control.
• Local governments must have a biosecurity plan that covers invasive plants in their area. This plan may include actions to be taken on Kidneyleaf mudplantain. Some of these actions may be required under local laws. Contact your local government for more information.