Hydrocleys nymphoides

Water poppy

Family: Butomaceae

Origin: South America

Water Poppy floating on water surface with a single flower.
Water poppy is an aquatic weed with rubbery stems that creep along the bottom of a pond. Leaves are thick and rubbery and can float on the surface of the water.
Photo credit: Holly Cox

Regional Pest Management Plan (RPMP) status

  • Whole region — Eradication
  • National Pest Plant Accord Species

View more about the RPMP statuses

General description

Perennial aquatic herb. Stems are rubbery and creeping. Leaves are thick, glossy and float on the water’s surface. Flowers are yellow with a purple centre, < 8 cm in diameter and borne in late summer.

What you need to know

To help protect our environment:

  • You must not breed, distribute, release or sell water poppy. As water poppy is a National Pest Plant Accord species, these restrictions apply within the Auckland region and across the whole of New Zealand.
  • You must not plant water poppy within the Auckland region.

Auckland Council will control water poppy at all sites where it is known to occur.

If you see water poppy anywhere in the Auckland region, please report it to Auckland Council at pestfree@aucklandcouncil.govt.nz.


Still or flowing water bodies < 2 m deep.


Vegetative spread from root fragments and new plantlets, dispersed by water movement. Human-mediated dispersal through deliberate plantings.

Impact on environment

Aggressive coloniser that forms dense mats on water surface. Shades out submerged vegetation and restructures aquatic plant and invertebrate communities.


Site management - recommended approaches

Do not attempt to undertake control of this species. Please report to Auckland Council.

Caution: When using any herbicide or pesticide please read the label thoroughly to ensure that all instructions and safety requirements are followed.

Water Poppy in a black tub with flowers.
A very fast growing plant that can cover the surface of a pond or lake quickly. Water poppy forms dense mats on the water surface that block out light to native aquatic species below.
Photo credit: Jonathan Boow