Monarto mintbush
The Monarto mintbush (Prostanthera eurybioides) is listed as nationally endangered with around 900 plants left in the Murraylands and Riverland region. Landscape board ecologists are working with the community to conserve the remaining Monarto mintbush through monitoring and by supporting landholders with known clusters of plants.
What is a Monarto mintbush?
The Monarto mintbush is a low spreading shrub with branches covered in dense, curled long hairs. It can grow up to 1 metre high and has pale purple, tubular-shaped flowers with brown and orange spots on the inside.
Monarto mintbush flowers between August and November. Its fruits are dark brown, woody capsules up to 2.4 mm long, with up to four segments. Capsules can be collected and dried between November and January, producing seeds that are brown oblong-shaped, typically 2.2 mm long and 2 mm wide, with a large plug at one end.
Where is Monarto mintbush found?
Monarto mintbush is endemic to South Australia and only found in two small, scattered populations: one at Monarto in the Murraylands and the other at Keith in the upper south-east. It has specialised habitat requirements and is associated with granite outcrops on sandy loam soils in Eucalyptus mallee woodlands.
Why are Monarto mintbush under threat?
The Monarto mintbush is under threat from a range of factors including climate change, introduced pest and plant species, grazing by overabundant native animals (such as kangaroos), habitat loss, and low genetic diversity.
Invasive weeds are easily able to outcompete mintbush seedlings, particularly weeds like oats (Avena sp.), perennial veldt grass (Ehrharta calycina), African boxthorn (Lycium ferocissimum) and bridal creeper (Asparagus asparagoides).
Monarto mintbush is very palatable and is susceptible to grazing by rabbits and domestic stock. Besides damaging adult plants and preventing regeneration, grazing by sheep may also result in soil compaction around the plants.
What is being done to protect Monarto mintbush?
Landscape board ecologists are working with landholders and other agencies to monitor known plant communities. This work includes regular surveys, and undertaking pest control work and fencing for additional protection. Some private properties with Monarto mintbush populations have protected them under a Heritage Agreement so the vegetation is conserved in perpetuity. Translocation of plants has also been undertaken in some important sites around Monarto.
How you can help!
Some of the ways that you can help preserve native plants include:
- Preventing damage caused by grazing.
- Preventing removal/illegal collection.
- Controlling weeds to reduce competition.
- Taking a photo instead of picking the flower.
- Volunteering with the Murraylands and Riverland Landscape Board or joining your local native vegetation group.
- Reporting any sighting of these endangered plants to our offices
What should I do if I see a Monarto mintbush?
If you are lucky enough to see a Monarto mintbush, the most important thing to remember is to not touch or remove it. Take a photo and be discreet about its location to protect it from illegal collection.
If you suspect you have a population of Monarto mintbush on your property, contact our ecologist who will help to formally identify the plant. They can offer you support and advice about this endangered species so you can play a vital role in conserving our unique native biodiversity.
This project is supported by the Murraylands and Riverland Landscape Board with funding through the landscape levies.