What does it look like?
White bryony has a soft, summer-green, cucumber-like vine (<6 m tall) that dies back in autumn to a huge, branching, brittle, perennial tuber (45-160 x 100-800 cm), oriented vertical to horizontal. Soft slender stems with coiling tendrils arise from the end of the tuber, with thin, 5-lobed leaves (<15 x 15 cm), with the middle lobe being the longest. Whitish tubular flowers (<2 cm long) with green stripes are followed by smooth-skinned, round, succulent fruits (4-8 mm diameter) from January to March that change from yellow to red and contain numerous seeds.
Tuber fragments are spread by water and soil movement. Seed is spread by birds.
Why is it a problem?
It grows rapidly, has a scrambling habit and persistent tubers, and can tolerate wet to seasonal drought, warm to cool temperatures, a variety of soils, and semi-shade. It’s poisonous so not browsed by animals. It smothers low canopy and shrubland and discourages native seedlings from establishing. It’s likely to invade disturbed and open forest and shrubland, and stream edges.
Control methods
If you suspect that you have found white bryony, do not touch it. This pest plant is under an active national eradication programme, and any attempt to get rid of it could accidentally spread the pest. MPI will work with you to control the weed. Tuber fragments resprout prolifically, so follow up tuber treatment is probably necessary for 2-5 years until eliminated.
Related links
Management Programme
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 informationNotifiable Organism
Some organisms must be notified to MPI if they're spotted in New Zealand. These include serious pests and diseases like foot-and-mouth disease, the rabies virus, fruit fly and disease-carrying mosquitoes. If a notifiable organism established in New Zealand, it could severely affect our primary production or trade and market access. If you spot a notifiable organism, you have a legal obligation under section 44 of the Biosecurity Act 1993 to tell MPI. Call the pests-and-diseases hotline on 0800 80 99 66.
The Biosecurity (Notifiable Organisms) Order 2016 lists notifiable organisms. New additions can be made by the Governor-General and MPI periodically reviews the list to ensure it is up-to-date.
Unwanted 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.
National Interest Pest Responses programme (NIPR)
Nine harmful weeds are managed under the National Interest Pest Responses (NIPR) programme. These pests could cause serious harm to New Zealand's environment and economy if they are allowed to spread.
More informationTaxonomies
FamilyCucurbitaceae
TypePlants
GroupClimber
HabitatLand
Management ProgrammeNational Pest Plant Accord (NPPA)Notifiable OrganismUnwanted OrganismNational Interest Pest Responses programme (NIPR)
