A native mint of the Sydney region that faces immediate threats from urban pressures can now be saved thanks to state-of-the-art techniques used by scientists at the Royal Botanic Garden, Sydney and University of Sydney.
Prostanthera marifolia (the sea-leaved mintbush) was thought to be extinct until it was discovered growing on Sydney’s North Shore. Since then, a passionate team of researchers has worked to understand this rare plant.
Royal Botanic Garden Researcher Dr Trevor Wilson said after 200 hundred years of intensive European occupation, large areas of Australia’s native flora have been lost to urban development.
“There are only three small populations of this species known to be growing in the wild,” Dr Wilson said. “We hope our research will increase awareness of the city’s amazing biodiversity before it disappears.”
“The Sydney basin shares many rare species and Sydney is the largest city in Australia. We hope that by being made more aware of our amazing biodiversity and the urban pressures endangering this biodiversity, Sydneysiders will see the value in preserving their bushland heritage and support projects that protect our critically endangered flora,” he said.
Royal Botanic Gardens and Domain Trust A/Executive Director Dr Brett Summerell said when possible seed or plant material from the mintbush will be collected and stored in the seed vault in the Australian PlantBank.
“We are prioritising saving rare and endangered species in NSW in the PlantBank to protect them against extinction as well as for possible land regeneration if and when it is necessary,” Dr Summerell said.
The team of scientists studying the plant include Drs Barry Conn and Trevor Wilson based at the Royal Botanic Garden, Sydney and Dr Murray Henwood and Kirstin Proft from the University of Sydney’s School of Biological Sciences.
Team Leader Barry Conn said they examined molecular and morphological data from specimens collected in the field as well as those preserved in herbaria (botanical museums) across the country. Their research focused on identifying and documenting the distinguishing characteristics of the plant.
“We believe that understanding what makes this mintbush unique is vital to its survival. As well as facing habitat loss and other urban pressures, we found the sea-leaved mintbush’s resemblance to another rare species, the villous mintbush, is a significant concern for its conservation,” Dr Conn said.
“A clear distinction between these two plants will help scientists, bush regenerators and policy makers properly identify this plant as well as prioritize the maintenance of every population for the preservation of both species,” he said.