Reporting the Chilean ayten
September 25, 2019
Chilean mayten jumps the garden fence – but you can help by reporting this pest tree
Researchers at Manaaki Whenua – Landcare Research and Environment Canterbury are calling on the public to report sightings of the problematic pest tree Chilean mayten.
Chilean mayten (Maytenus boaria) is a South American evergreen tree native to Chile and Argentina. The tree can grow up to 30 metres tall, and when fully mature resembles a weeping willow.
Male specimens of the tree were brought to New Zealand in the late 1800s and sold commercially. This wasn’t a problem until the mid-1980s, when female seed-grown trees started to appear on the market in New Zealand.
Female flowers produce fleshy fruit that are attractive to birds, so Chilean mayten has quickly dispersed well beyond its original plantings to colonise new areas.
It is now an extremely difficult weed to remove. It steadily produces suckers that, in some growing conditions, can form dense thickets more than 10 metres away from the parent tree.
The tree’s weedy tendencies saw it listed on the National Pest Plant Accord (NPPA) in 2012, making it illegal under the Biosecurity Act 1993 to propagate, distribute or sell the plant, either casually or through nurseries. It is also a ‘plant of interest’ in Canterbury’s Regional Pest Management Plan for 2018–2038.
As a result, biosecurity researchers are asking the public to report examples of Chilean mayten to the iNaturalist NZ website so that the scale of the problem can be understood.
“As a shrub, Chilean mayten looks a lot like a native New Zealand plant, resembling a small-leaved māhoe (Melicytus) or perhapsHoheria,” explains Murray Dawson, a researcher at Manaaki Whenua.
When it is still establishing the plant looks rather nondescript, with small, evergreen leaves and few distinguishing features, making it difficult to spot.
“Because it blends in so well, Chilean mayten can easily be overlooked, especially since its shade tolerance allows it to grow among other plants and later out-compete them,” adds Dawson.
Reported sightings of Chilean mayten can be added to the iNaturalist NZ website. If possible, close-up photos of identifying features such as leaves, small flowers, fruit or bark should also be posted, along with the tree’s location, for researchers to determine if the plant is male or female.
In Canterbury, researchers are running a competition and giving away $500 worth of spot-prize giveaways for photos of Chilean mayten. In addition, the Environment Canterbury Biosecurity 'Eagle eye' Shield will be awarded to the individual with the most confirmed Chilean mayten sightings in Canterbury during August, September and October 2019.
For more details on the competition, go to iNaturalist NZ: https://inaturalist.nz/projects/canterbury-chilean-mayten-hunt