Mexican Water Lily

Mexico, North America

General description

Perennial, bottom-rooted aquatic herb. Rhizomes are stout and erect. Stolons are creeping and tuberous. Leaves are floating, round, heart-shaped, < 20 cm in diameter and green with brown flecks on top, with a pink/purple underside. Flowers are yellow, < 15 cm in diameter and borne above the water surface in October – December. Fruit is spherical to ovoid, < 2.5 cm diameter and ripens in summer – autumn.

What you need to know

To help protect our environment:

  • You must not breed, distribute, release or sell Mexican water lily. As Mexican water lily 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 Mexican water lily within the Auckland region, unless you are transferring an existing plant on your land to another location within the boundaries of the same property.
  • You must destroy any Mexican water lily on land that you occupy if it has been planted in breach of the above rules and you are directed to do so by an authorised person.

Still and slow-moving freshwater bodies.

Seeds dispersed by water movement. Vegetative spread from rhizomes and tubers, dispersed by water. Human-mediated dispersal through deliberate plantings.

Forms dense mats and may displace submerged aquatic plants. Reduces dissolved oxygen levels, affecting fish, zooplankton and other native species.

Site Management

Follow up treated areas 3 times per year.

Recommended approaches

Physical control

Method: Mechanical removal or pull out

Plant parts requiring disposal: All parts

Disposal options: Remove to greenwaste or landfill if practical


Biocontrol is currently not available for this species.

Community agrichemical control recommendations

Certified Handler/Experienced agrichemical user
Foliar spray emergent foliage with 300ml glyphosate green per 10L of water

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

Similar species

Nymphoides geminata

Marshwort has thin stolons either on top of substrate or beneath water surface. It lacks large rhizomes.

fringed water lily
Nymphoides peltata

Fringed water lily has thin stolons either on top of substrate or beneath water surface. It lacks large rhizomes. The petals have fringed edges.

water poppy
Hydrocleys nymphoides

Water poppy has an inflated mid-vein on the underside of the leaves.

yellow water lily
Nuphar lutea

Yellow water lily has less rounded leaves and larger spongy rhizomes.

common water lily
Nymphaea alba

Common water lily has horizontal rhizomes whereas Mexican water lily has vertical ones.

Search tags

RPMP status

National Pest Plant Accord Species
Whole region (Sustained Control)
Mexican water lily - Main species image