What does it look like?
Yellow water lily is a perennial aquatic plant, with both floating and submerged leaves. Floating leaves are oval, up to 30cm long by 40cm wide, with a deep indent at one end. Leaves are tough, leathery, and dark green. Stout tuber-like rhizomes up to 10cm in diameter grow on the bottom to a depth of 3m. Stalked, solitary buttercup-like 4-6cm diameter flowers rise well above the leaves. Flowers have a strong alcoholic aroma. Fruit are 2-3cm long, green and flask shaped and contain hundreds of long-lived viable seeds.
Why is it a problem?
Yellow water lily grows from the water's edge into slow-running water up to 2m deep and can invade permanent water of lakes and slow-flowing streams over mud and silt. Fast growing, along with its massive rhizomes that hold nutrient stores, enables it to outcompete all other aquatic plants.
Control methods
If you have seen or suspect the presence of yellow waterlily, you must report the sighting to us immediately.
More information
As of 2024, yellow water lily is considered eradicated from Hawke’s Bay. Previously, it only occurred in two sites in the Elsthorpe area.
Related links
- Hawke’s Bay Regional Council Pest Management Plan 2018-2038
- NPPA and the control of weeds | NZ Government
Notify Council
If you think you've found this pest, please get in touch with our Biosecurity Team at biosecurity@hbrc.govt.nz or call us on 0800 108 838.
Management Programme
Eradication Programme
To reduce the infestation level of the subject, or an organism being spread by the subject, to zero levels in an area in the short to medium term.
National Pest Plant Accord (NPPA)
The NPPA is designed to prevent the sale, distribution and propagation of a set list of pest plants (the Accord list) within New Zealand. If allowed to spread further, these pest plants could seriously damage the New Zealand economy and environment.
More informationUnwanted Organism
An unwanted organism is any organism that's capable of causing harm to natural or physical resources (like forests and waterways) or human health. A number of introduced pests in New Zealand are classed as unwanted.
Rules
Sections 52 and 53
Sections 52 and 53 of the Biosecurity Act 1993, which prevent the communication, release, spread, sale and propagation of pests, must be complied with.
Taxonomies
TypePlants
GroupFloating
HabitatFreshwater
Management ProgrammeEradication ProgrammeNational Pest Plant Accord (NPPA)Unwanted Organism
RulesSections 52 and 53
