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
All plants on MPI's National Pest Plant Accord (NPPA) are unwanted organisms under the Biosecurity Act 1993 whose formal or casual trade contributes significantly to their spread.
Plants on the Accord cannot legally be propagated, distributed, or sold in New Zealand. If allowed to spread further, these pest plants could seriously damage our economy and environment.
Notifiable Organism
Any organism specified under the Biosecurity Notifiable Organisms Order 2016 must be reported to MPI if spotted. If any of these organisms become established in New Zealand, they could severely affect our primary production, 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.
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.
More informationNational Interest Pest Responses programme
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 AccordNotifiable OrganismUnwanted OrganismNational Interest Pest Responses programme
