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  • RBG

Saving the Leafy Anchor Plant from Extinction in Orbost

It was 2011 when David Robbins, team leader of the nursery at the Melbourne Gardens, and his colleagues were approached by the Department of Environment, Land, Water and Planning to propagate 100 Leafy Anchor Plants (Discaria nitida), a rare and threatened plant, and reintroduce the species to the Orbost region. With only a few Discaria nitida left in the wild, and extinction of these plants likely to have negative repercussions for the surrounding habitat, it was imperative that the nursery team found a way to make the project work.

Of the 20 cuttings they were presented with, only two survived. The survivors, however, which have matured, managed to produce 300 seeds which were collected in early summer of 2018. The issue with the next step, germinating the seeds, was that there was virtually no information on how to do it. “You’d do research online and ask other people and they’d say no idea, never done that before”, David said of his attempts to discover more information. Using what little information they had to go on, and with trial and error as the only feasible option, David and the nursery team tried a range of different germination strategies.

With different methods in progress, and not necessarily expecting success, the nursery team sent some Discaria nitida seeds to the Herbarium, hoping Seed Bank volunteer Bob Hare could weave some magic by treating the seeds with gibberellic acid, a naturally occurring plant hormone which assists growth. 12 days later came the eureka moment for the Nursery Team. “An email came back saying we’ve had something like 50% germination from those seeds, we can bring them down. It was wow”, David said.

The seedlings are currently in coir plugs and will be tubed up and planted as they mature. The success of the project has been a triumph for the Nursery team, especially due to the rare nature of the plant and lack of information on how to propagate it. “We’re among the few people to have ever seen Discaria nitida seeds germinate”, David said of the project. Since their triumph with gibberelic acid, another method they tested has proved effective - cool moist stratification. It involves 'tricking' the seeds into believing they're experiencing winter by subjecting them to cold, moist conditions which can trigger germinaion once the seeds are sown, and in the case of the Discaria nitida seeds, it worked! With both of these methods successful, the team now have 400 Discaria nitida seedlings pricked out. 

Propagating and translocating rare and threatened plants is something the nursery team is familiar with. They have worked on a range of similar projects, including reintroducing the Mountain Swainson-pea (Swainsona recta), which was extinct in Victoria, to the Chiltern-Mt Pilot National Park. David’s colleague, horticulturist Chris Jenek, who looks after research, has active propagation projects running for roughly 80 different plant species. While these projects are run by the Nursery team and not open to the public, there will likely be opportunities for the public to volunteer to assist with planting out of the Discaria nitida plants once they’re ready to be reintroduced to their natural habitat.


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