Busting a botanical myth
The NT’s Palm Valley was long thought to have been a surviving relict of Australia’s prehistoric rainforests, but we now know its trees arrived much more recently with Aboriginal horticulturalists.
John Pickrell is the editor of Australian Geographic. He is a science writer, author, nature lover and self-confessed geek. Blog posts range over Southern Hemisphere palaeontology, dinosaurs, megafauna, archaeology, palaeoanthropology and a smattering of other topics.
FINKE GORGE National Park, 120km west of Alice Springs in the Northern Territory, covers a vast and striking stretch of the Red Centre. Its ghost gums and outcrops feature in many of the watercolour landscapes of artist Albert Namatjira, who was born in the neighbouring community of Hermannsburg.
One of the most visited spots in the park is Palm Valley, with its population of up to 12,000 red cabbage palms (Livistona mariae), which fill the gorge and crowd the banks of the ancient Finke River. The tree is an endemic species and the only palm found growing in outback Australia.
The story once told to visitors, and marked on information boards in the park, was that the palms were the descendants of trees that had been growing here for 15 million years or more.
Natural water sources had allowed them to persist, it was said, while elsewhere in the outback the trees had died out. “Palm Valley is a remnant of the rainforests that once covered our ancient continent,” claims the text of an NT government website that is yet to be updated.
The red cabbage palm’s closest relative, the Mataranka palm (Livistona rigida), is found at its closest points 800–1000km north of here, at two sites on either side of the Gulf of Carpentaria.
In 2012 an international team of researchers, including the University of Tasmania’s Professor David Bowman, decided to test the relatedness of the two palms, and what they found baffled them; the two species were genetically indistinguishable. An analysis of the DNA further suggested that red cabbage palms had been a distinct population for just 15,000–30,000 years.
An intriguing conundrum
This presented an intriguing conundrum – how had the trees ended up nearly 1000km south? There are no rivers to have carried seeds here, and if bats or birds had brought them in their guts, why had they not given rise to any other populations of the palms at suitably wet locations along the way?
This led the researchers to speculate that the palms had been brought here by Aboriginal people as they colonised the inland of the continent within the last 30,000 years. Livistona are among the few Australian palms that are edible as young plants, and they can also be cultivated.
In 2015 David and his colleagues backed up this theory when they published yet another interesting discovery in the journal Nature. They had found a recent translation of the writings of German anthropologist and missionary Carl Strehlow, who, in 1894 recorded a local Aboriginal story.
Passed down across the generations, this tale recounted that palm seeds had been brought to the Red Centre by “the gods from the high north…a long time ago”.
Livistona palms on the Mpulungkinya Walk at Finke Gorge National Park. (Credit: NT Government)
Strehlow himself had noted: “Here are beautiful 40 to 50 feet high palms, here surrounded by gumtrees and acacias and the herbs and flowers at their base release a sharp smell. The whole scenery reminds of a botanical garden.”
The discoveries have set the record straight about the palm trees of central Australia, and have also provided another example of how Aboriginal lore – passed down from parent to child and purely through oral tradition – has recorded ancient truths about the world with remarkable accuracy.
Other phenomena thought to be recorded in Aboriginal teachings across Australia include supernovae that created temporary bright stars in the sky, meteorite impacts that explain modern craters and the presence of strange, giant animals that were likely to have been extinct megafauna.