Myrtle rust is a "disaster in the making".
That's the warning from a leading botanist as the disease infiltrates the South Island with no way of stopping it.
Botanist Peter de Lange told Newshub "we're going to see more and more myrtle rust".
That's because it's an invasive disease that can't be eradicated - threatening native flora.
"Until it does develop some resistance which we've got to hope it does, we're going to see a lot of damage, a lot of death and possibly extinction. It's not good."
Canterbury is new territory for the disease. The map below indicates reports of myrtle rust - showing just how widespread the disease is in the North Island.
And with a closer look, the disease can be seen creeping south.
Environment Canterbury principal advisor Laurence Smith told Newshub because it's spread by spores "it's bound to be in a lot of other places" that haven't even been reported yet.
Now experts like Smith want people to report those sightings and take care when treating it.
"You can cut it out. You may have to cut out all the plants that are affected and some of the myrtle species around it and put it into landfill."
One place where it is doing some good is on the Chatham Islands. There are no endemic myrtles, so the disease is eating away at highly-invasive plants.
"Myrtle rust loves Chilean guava so in a funny kind of way, it's kind of a silver lining," said de Lange.
On the mainland though, there's no such relief. Iconic plants including pōhutukawa and mānuka are in the firing line.
"Our flora's never seen it before so it's a bit like what COVID did to humans. We'd never seen it before, we have to develop resistance."
The future of some of our most loved natives depends on it.
