The Mystery Surrounding Australia’s Ancient and Endangered Wild Macadamia Trees

Ian McConnachie is eager to find the answer to an age-old mystery – just how many hundreds of years have the wild macadamia lived in Australia?

Aboriginal and Torres Strait Islander readers are advised that this article contains photos and names of people who have died.

After decades of visiting precious remains from the habitat of a threatened species in Queensland’s Amamoor State Forest, the founder of the Macadamia Conservation Trust has already discovered that appearance can be deceiving.

“A lot of people are familiar with macadamia, but seeing it in a rainforest is very bewildering,” said Mr. McConnacht AM.

“Nothing as you would expect, they are hiding among all the other trees.”

Living time capsules

An old man in a cardigan looks at the jagged leaves of a wild macadamia tree that doesn't even reach his chest.
This macadamia tree hasn’t grown in over 40 years, says Ian McConnaci.(ABC Rural: Jennifer Nichols)

Describing himself as a “Macadamia Dinosaur”, retired food scientist, field researcher, grower and avid historian, McConnaci chose a tree with a high chest, as the perfect example of how a young plant could be hundreds of years old.

“It only has 18 leaves,” he said. “I first saw it in 1979, and between 1979 and now, it didn’t grow at all. It just sits in the rainforest in thick shade, just waiting for the light to come on.”

The oldest planted macadamia tree in Europe has been grown in the Brisbane Botanical Gardens since 1858 and still bears a healthy crop of nuts.

Craig Hardner dwarfs in front of the oldest planted macadamia tree.
This is the oldest macadamia tree planted in Europe in the world, says Craig Hardner.(Supplied: UQ)

“One of the initiatives we are taking is that we are starting to do radiocarbon dating of trees in rainforests so that we can know how long they are and how old they may be,” said Mr. McConnachi.

Three years ago scientists made the “shocking” DNA discovery that the global macadamia industry sprang from a single tree, or small group of trees, in Mulu.

“There are probably 100 million macadamia trees planted around the world that all originate from a single mother tree very close to here,” said Mr. McConnaci.

Macadamia, which is valued and traded by the First Nations peoples of Australia, is the only plant in our country that has become a world food.

Black and white portrait of a gray bearded Aboriginal man with a
Pelin gathered the older Pelin in Yogambi and his people and traded macadamia nuts with the Europeans.(Supplied: John Oxley Library, Qld . State Library)

The nuts were transported to Hawaii in 1881, where the crop was first marketed.

Macadamia Trust director Andy Burnside estimated that clearings, urban encroachments, fires and weeds have destroyed up to 90 percent of the wild population.

Three people standing near an old tree
Paul O’Hare, Mary Burton and Andy Burnside in the birthplace of the world’s macadamia trees.(Supplied: Southern Cross University)

All four species are listed as threatened. With permission, cuttings were taken from wild trees.

“The genetic base of our commercial industry is very narrow,” Burnside said.

“What we’re trying to do is preserve some genetic material from the wild tree populations and plant some trees in a safe environment in many trees in different locations in eastern Australia.”

Pest and disease resistance, scale and adaptability to climate are just some of the traits these wild trees can provide to protect the world’s genetically endangered commercial crops.

Nuts hanging on a tree.
Macadamia nuts grow near Lismore in northern New South Wales.(ABC Rural: Kim Hunan)

business cracking

The Australian Macadamia Society has estimated that the value of the global macadamia farm will be $1.63 billion this year.

“We sampled more than 600 wild macadamia trees and studied their DNA markers,” McConnaci said.

“We are only aware of the huge diversity of genetics and this is very important for the future.”

Flat sandy walkway leading into the rainforest.
The Walk with Wild Macadamia Trail is easily accessible.(ABC Rural: Jennifer Nichols)

A new walk has opened with the Wild Macadamias Trail, including interpretive signs, off the Amama Day area in the Amamoor State Forest – off the beaten path that Australian country music fans lead on their annual pilgrimage to Gympie’s Music Muster.

A First Nations man with a beard holds a wild Macadamia leaf.
Gubbi Gubbi, Wakka Wakka and Kullilli is a Russell Bennett enthusiastic man for his country.(ABC Rural: Jennifer Nichols)

Traditional owner, Russell Bennett, hopes ecologists will starve to learn more about the delicious nuts and their habitat.

“I was born and raised in Jimbe. I am Gobi Gopi, Waka Waka, Kulele. This is my country. I have been a guardian all my life and look after this country,” he said.

“I really hope we can highlight the importance of these macadamia nuts here so that we can conserve them and therefore the bush that you live in.”