Stout horizontal rhizome up to 60mm across. Stems are spongy, up to 3 m long. Leathery leaves round to elliptic (10 – 25 cm diameter) with a deep sinus, green or pink on the lower surface with a distinct main vein. Flower (Jan-Jun) white or pale pink with a yellow centre (hybrids can have red, yellow or blue flowers) and are up to 20cm across, these float on or just above the water surface from long stems that arise from the roots.
In water up to 2 m deep. Open still-slow moving water in lakes, dams, ponds.
Rhizome extension and fragmentation, rarely by seed. Deliberate plantings.
Can grow quickly in warm open water bodies. Thick dead stems can float to the water surface where they collect silt and create a floating mat that can become habitat for other weeds such as gypsywort. Shades out submerged native species and can reduce habitat for bird species that need open water.
Always begin treatment at top of catchment and work downstream. Follow up as required.
1. Mechanical removal.
2. Spray emergent foliage (300ml glyphosate/10L, use glyphosate formulation approved for use over water). Repeat as necessary.
Caution: when using any herbicide or pesticide PLEASE READ THE LABEL THOROUGHLY to ensure that all instructions and safety requirements are followed.