Kidney leaf mud plantain 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 not a declared Noxious Weed in NSW, however declaration is being considered as a Category 1 weed.

It is 20-50 cm tall and can form thick colonies which usually emerge 10-30 cm, but can be up to 50 cm, above the water’s surface.

The leaves are bright glossy green, kidney shaped (1-4cm long, 1-5 cm 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 outcompete native vegetation and 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.