Identification and Reproduction

Identification:

• Yellow floating heart is a herbaceous, perennial, aquatic plant that roots at the bottom of waterbodies. 
• Floating leaves were cordate shaped, ranging from 3-15 cm wide and green to yellow-green in colour. Undersides of leaves were purple. Leaves also had slightly wavy margins and attached to underwater rhizomes. 

• It produces bright yellow flowers that sit above water on green stalks. Each individual flower is composed of 5 petals. Blooms occur from July to September. 

Reproduction:

• Reproduces vegetatively through underwater stolons. If broken off it can reroot and produce a new shoot. 
• It also produces seeds that are flat, oval with tiny hairs. These hairs help them float as well as attach onto objects or animals for further dispersal. 

Habitat & Ecology

• Grows well in slow moving waters so it can anchor itself to the ground. It is common in lakes, rivers, ponds and marshes. 
• It will also take over ditches, canals, waterways and dikes. 
• Typically found in eutrophic, alkaline waters that are under 3 m deep. 

Impacts

Social: 

• Large infestations will inhibit recreational activities such as swimming, boating and fishing. 
• It can also block irrigation canals. 
• Its presence can also change the aesthetics of the waterbody.

Ecological: 

• Forms dense mats that will out shade native aquatic species. 
• Reduces biodiversity. 
• As it slows water flow make the water stagnant and lower dissolved oxygen levels. 
• Can disrupt the food web. 

Management

Prevention is a high priority for this species. 

• Refrain from planting and distributing this plant. 
• Never dispose of unwanted aquarium material in natural waterbodies. 

Mechanical/Manual Control: 

• Careful hand-pulling can successfully remove the plants. Use shears and other hand tools to cut stems. Be sure to collect as much as the underwater roots as possible. 
• Hand raking can be effective if the ground is loose. That way the plants can be uprooted and removed off site. 
• Using benthic barriers can help control yellow floating heart. 
• Mechanically harvesting the plant can also be used. But should be used with caution as separated plant fragments can regrow. 

Resources

For more details check out the Invasive Species Compendium datasheet on Nymphoides peltata (yellow floating heart). 

Header photo (Krzysztof Ziarnek).