There’s a nasty new plant disease, with depressing implications for the future of Australian vegetation, that we should all know about - and report if we ever see it here.
It begins as purple spots on leaves, which develop into bright yellow, powdery pimples, and deforms all the affected parts of the plant, stunting it, and possibly killing it. (An internet search will show you photos.)
Myrtle rust is caused by the fungus Uredo rangelii. It was first found in Australia in Gosford NSW, in April 2010, whence it has spread rapidly to other states. It was first found in Queensland in Dec 2010 and has now travelled as far as Cairns. It is carried by the wind, insects and other animals, and of course by people who buy, sell, and transport plants. Even your shoes, clothes, packaging material, and so on, can transport it.
It is native to South America, but also exists in North America and Hawaii. We may never know how it got here, but it is very infectious, so could have hitch-hiked on anything or anyone coming from any of those places.
It seems to only affect plants in the myrtle family MYRTACEAE. Unfortunately, the most iconic Australian plants are in that family. This is a disease with the potential to transform beautiful landscapes into ugliness, and its economic impact is likely to be considerable.
Where would we be without gum trees, ironbarks, stringybarks, applegums, brush box, turpentines, bottlebrushes, teatrees, lillypillies, lemon myrtles, golden pendas... ?
The list of exotics that are also susceptible is long as well. (It includes New Zealand Christmas Trees, and guavas.)
For a full list of plants known to have been affected, see http://www.dpi.qld.gov.au/4790_19789.htm
For the potential total list, see
If you suspect Myrtle Rust on your property, in the bush, or in a park, garden, or nursery, please notify Biosecurity Queensland on 13 25 23 or call the Exotic Plant Pest Hotline on 1800 084 881.
For further information and printable documents to help identify the disease visit Biosecurity Queensland at: http://www.dpi.qld.gov.au/4790.htm