Bush-tucker plants were spread by hand across mountainous regions in New South Wales by Indigenous people, according to a new scientific theory published today.
Newly published DNA research from a team of scientists and indigenous collaborators upturns botanical history, pointing to a vast and unacknowledged human influence in the distribution of Australia's native plants.
Maurizio Rosetto, a botanist with the Royal Botanic Gardens, launched a project to map DNA of the black-bean tree around Lismore, hoping to genetically trace its journey from the wet tropics to the North Coast's rainforest ridges.
"We were wondering how it could be found so far away from water, inland, a few hundred kilometres inland, and uphill as well," he said.
The results surprised him.
Instead of revealing genetic diversity, he found that in NSW all trees share a common ancestor gene, being descended from "a single mother seed".
It is strong evidence that Indigenous people carried, shared, or even traded the seeds as a valuable food, as they migrated along peaks of the Great Dividing Range.
Incorporating Aboriginal knowledge
In the next research phase, collaborator and cross-cultural ecologist at Macquarie University Emilia Ens sought out Indigenous elders with living knowledge of the plant to help substantiate the theory.
"Aboriginal people say they'd move plants around the landscape just like we do today as well." she said.
"We're moving, you know, grandma's favourite daisies from your garden to her garden.
"That's probably what happened in the past, with bush-foods."
Oliver Costello is a Bundjalung tribe member and one of many cultural collaborators on the project who investigated groves where black-beans grow.
He has welcomed the collaboration with scientists, and hopes further DNA research will answer more questions about the bean.
"There's some really important questions I have about this research, about how did the beans get here — was it migration, was it trade, was it gifts?" Mr Costello said.
Elders highlight importance of black-bean tree
Mr Costello said many elders shared cultural knowledge with the team, highlighting the tree's importance.
"It was a food source that people would gather around seasonally, and be able to have large gatherings," he said.
"And it became quite important for ceremony and knowledge exchange.
"There are also really important stories about the sacredness of the tree."
