Kidney leaf mud plantain

Kidney leaf mud plantain forms thick
mats.
Has the ability to out-compete native
vegetation.
A leaf rises above the water surface.

Kidney leaf mud plantain (Heteranthera reniformis) is an aquatic plant native to North, Central and South America. It grows well in disturbed shallow freshwater habitats. It was introduced into Australia as a pond pant, with escaped plants colonising freshwater streams, ponds and mudflats.

Kidney leaf mud plantain (KLMP) is a declared class 1 noxious weed in NSW.

  • It is 20-50cm tall and can form thick colonies that usually emerge 10-30cm, but can be up to 50cm, above the water’s surface.
  • The leaves are bright glossy green, kidney-shaped (1-4cm long, 1-5cm across) borne on stalks (2-15cm long) in alternative arrangement.
  • The flowers are in clusters (racemes) with each cluster containing 2-10 small white or pale blue flowers with six petals. The fruit is a small capsule containing tiny winged seeds.
  • KLMP can grow submerged or floating, with stems that either creep along the mud or float. It can produce roots at the nodes, particularly where they come into contact with the soil.
  • It prefers open, sunny sites with nutrient-rich soil and shallow water less than 15cm deep. It is often found in roadside ditches, or on the edges of streams and ponds.

It is a popular ornamental pond plant and is actively promoted and sold in the aquarium trade for its attractive foliage, which has lead to its escape and spread in the Australian environment. It is dangerous because of its quick growth, mat-forming habit, and its ability to out-compete native vegetation; it has the potential to be a serious weed.

It is a major weed in rice crops and a new weed to the Far North Coast.

The shallow growing depth suggests that KLMP may allow mechanical removal, however as the plant can reproduce vegetatively, this may lead to further spread through fragmentation. If mechanical or manual removal is to be undertaken, strict hygiene protocols will have to be implemented and followed. The added disturbance will encourage seed strike, hence follow-up treatment will be required.

Distribution map as at October 2016 

Predictive mapping supplied by Queensland Biosecurity