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Mount Everest and the eucalypts of eastern Australia
The snowy slopes of the world’s tallest peak might not seem to have much in common with endangered plants in eastern Australia, but to PhD researcher Tasha James they have a special significance.
Tasha surrounded by flowering Boronia imlayensis, a critically endangered plant species unique to Mount Imlay in New South Wales. Photo by Emily Brown, courtesy of Tasha James.
Meet Mount Imlay
In the far south-east of New South Wales sits a sentry of the landscape known as Mount Imlay or, to the local Indigenous people, Balawan. The mountain reaches almost 900 metres of elevation.
The area surrounding this peak, aptly named Mount Imlay National Park, was reserved for conservation in 1972. Within the 3,000 hectares of the park are a range of endangered flora and fauna. With wildflowers in spring and wildlife of all kinds all year round, it’s no wonder the National Parks Association of New South Wales describes the site as a botanical treasure.
Treasures aren’t automatically protected, though, and this lesson was learnt the hard way when Mount Imlay and the park around it burnt extensively during the Black Summer fires of 2019 and 2020. Should you hike to the summit of Mount Imlay, you might be able to see as far as Mallacoota, which too was severely burnt.
Today, Mount Imlay is officially recognised as an ‘asset of intergenerational significance’. Across New South Wales, 360 sites of significance have been declared to help protect 132 threatened plants and animals. Perhaps more familiar among the species on the list are the Wollemi pine and the koala, but the Kaputar rock skink and the spotted tree frog are also there. Two others on the list are known only to Mount Imlay: the Imlay mallee (Eucalyptus imlayensis) and Connie’s guinea flower (Hibbertia circinata). These plants, along with the pink flowered Boronia imlayensis pictured above, are the focus of Tasha James’s PhD research.
Tasha at the top of Mount Imlay. Photo by Melea Vera, courtesy of Tasha James.
Tasha and the mallee
Tasha James was drawn to science by the opportunity to learn about the natural world and apply what she’s learnt to real-world challenges. In the Imlay mallee and its critically endangered counterparts, one could say she’s found just that match.
One of the rarest of the eucalypts, the Imlay mallee is a tree with a dense canopy of glossy green leaves, bark that sheds in ribbons and flowers that bloom small and white. As of 2011, a population of just 60 to 80 trees was known to exist in just one spot. That spot is just below the summit of the mountain with which it shares its scientific name, among the very vegetation burnt in the Black Summer fires.
Although Tasha never saw the forest of Mount Imlay before the fire, her research colleagues have. Data from field surveys and samples Tasha has collected since, together with information drawn from herbarium records and living collections, will contribute to a knowledge base for the study of threatened species after fire, Boronia and beyond.
Tasha extracting DNA from leaf samples. Photo by Laura Simmons, courtesy of Tasha James.
Back on Mount Imlay, researchers are tracking the regrowth of vegetation but haven’t identified any new Eucalyptus imlayensis seedlings since the fire. Based on an absence of those little white flowers, the mallee trees that survived aren’t expected to produce seeds for several years.
In circumstances like these, seed banks are particularly important, for both conservation and research purposes. The smaller the remnant population of a species, the less genetic diversity there is. The less genetic diversity there is, the more a species is susceptible to the many and varied threats of the modern world.
This makes the research of Tasha and her colleagues all the more important, not only to understand the population genetics of surviving plants but to build the foundations for new populations in the future – no matter how many trips it takes.
In the course of her fieldwork traversing the slopes of Mount Imlay to date, Tasha has climbed the equivalent of Mount Everest - twice! After such a trek, who wouldn’t care for a cup of tea!
Acacia tea in the laboratory
Before Tasha embarked on her PhD, she became acquainted with Australian flora through work at the CSIRO herbarium, as she helped to rehouse the plant collection preserved in ethanol. Her work with plants at CSIRO has continued, and these days, as a seed germination technician, she conducts seed viability testing.
For some species, including many Acacias, this testing process involves a step you might have now guessed: brewing a very special scientific tea. The seeds to be tested are placed in a tea strainer just like the one you might have at home before being placed in a beaker of water atop a hot plate. The water is boiled to break the tough seed coat and set the seeds on course to sprout.
The freshly boiled seeds are placed onto vermiculite, a growing medium that holds water well, and then given time to germinate. How long they take depends on the species – and sometimes it’s the time they take that researchers are interested in. Once the seeds start to show signs of life, then it’s time to count.
Germinating Corymbia maculata seed being tested for viability. Photo courtesy of Tasha James.
Counting seedlings is a calming and peaceful process, Tasha reports. The germination data gathered informs collection protocols more broadly, providing staff at the Australian Tree Seed Centre with propagation information and peace of mind about the potential of the seeds they store.
It’s important to know, for example, how long you can store seeds for after they are initially collected and how cold they should be kept. Seeds from plants that call high altitudes home can usually be kept colder for longer.
While the seedlings pictured above are those of the spotted gum, a range of other species undergo seed testing. These include seeds of the iconic wattle, which even have their own day of recognition on 1 September. Tess Corkish from the CSIRO shared some fun wattle puns in honour of National Wattle Day last year.
Jokes aside, the study of wattle seeds has gone beyond the lab bench, with golden wattle seeds sent to the International Space Station in 2020 to see how microgravity would affect their growth. Time will tell, but in the meantime you can read more about space in the World Space Week and Astronomers and the Animals contributions to the Pint of Science blog.
Back on land, stored seeds and dedicated research continue (and are critical) to support critically endangered species like the Imlay mallee. Through her work with both, Tasha shows it’s possible to find both peace and purpose working with plants.
To learn about other species at the centre of CSIRO research and see Acacia tea brewing for yourself, visit the Wild Files.
References
CSIRO. (n.d.). Wild Files: Wattles.
CSIRO. (2025). Australian Essential Oil Species Profiles. Available at: https://www.csiro.au/en/about/facilities-collections/Collections/ATSC/essential-oils
Department of Climate Change, Energy, the Environment and Water. (2023, August 31). Imlay Mallee. Priority Plants. https://www.dcceew.gov.au/environment/biodiversity/threatened/action-plan/priority-plants/imlay-mallee
Eucalyptus imlayensis - Growing Native Plants. (2015). Anbg.gov.au; Australian National Botanic Gardens, Parks Australia. https://www.anbg.gov.au/gnp/interns-2011/eucalyptus-imlayensis.html
Foley, M. (2021, November 24). Saving Australia’s rarest tree after Black Summer catastrophe. The Sydney Morning Herald. https://www.smh.com.au/politics/federal/saving-australia-s-rarest-tree-after-black-summer-catastrophe-20211124-p59bou.html
Jonsson, S. (2015). Eucalyptus imlayensis. Growing Native Plants; Australian National Botanic Gardens. https://www.anbg.gov.au/gnp/interns-2011/eucalyptus-imlayensis.html
Mount Imlay National Park. (2025). NSW National Parks. https://www.nationalparks.nsw.gov.au/visit-a-park/parks/mount-imlay-national-park
NSW National Parks and Wildlife Service. (1998). Mount Imlay National Park Plan of Management. https://www.environment.nsw.gov.au/sites/default/files/mount-imlay-national-park-plan-of-management-980125.pdf
NSW National Parks. (2021). Conservation: Assets of Intergenerational Significance (AIS). Available at: https://www.nationalparks.nsw.gov.au/conservation-programs/assets-of-intergenerational-significance.
Sapphire Coast. (2019). Mount Imlay National Park. https://www.sapphirecoast.com.au/mount-imlay-national-park
Simmons, C.L., Wright, G.T., McDougall, K.L. and James, E.A. (2023). Conservation and genomic diversity of a rare tree, Eucalyptus imlayensis (Myrtaceae), regenerating after wildfire. Muelleria: An Australian Journal of Botany, 41, pp.17–28.