The tiny tree is a descendant of a Gingko tree (Gingko biloba) that survived the 1945 bombing of Hiroshima and now has a new home at the Crawford Amphitheatre at ANU.

ANU chancellor Gareth Evans was joined by Sumio Kusaka, ambassador for the Japanese embassy, and James Carouso, deputy chief of mission from the US embassy, as the tree was planted in the ANU grounds on Thursday.

"The idea is to not only have something which reminds people of the horror of 1945 but also the idea of regeneration, regeneration of hope that we can create a safer and saner world if we put our political minds to it," Professor Evans said.

"It's an ongoing process to try to get the world to move away from some belief in the continued utility of nuclear deterrence and to recognise that so long as any nuclear weapons remain, others will want them.

"They're bound one day to be used and we're looking at an event in that case which would destroy life on this planet as we know it so it's ... [a] serious problem the world now has and this tree is meant to be a constant reminder."

Professor Evans reflected on his experience travelling through Hiroshima as a young backpacker, furthering his pursuit of a world free of nuclear weapons.

"The bombing of Hiroshima and Nagasaki marked a catastrophic turn for the worse in the history of humanity," he said in his speech.

"Out of the ashes of Hiroshima a better and more humane world can indeed grow. That is the core idea behind this tree-planting, part of a worldwide planting in appropriate sites around the world of seeds or saplings from Hiroshima's A-bombed survivor trees."

The tree was presented to ANU by Green Legacy Hiroshima, which was established to safeguard and spread the seed and saplings of Hiroshima's atomic bomb survivor trees, promoting a message of peace and hope for a nuclear-free world.

Professor Evans said the tree was also a symbol of optimism and hope.