Opinions are divided on eucalyptus trees. In some places, they’re a fast-growing cash crop. In others, they’re an invasive species.

In Australia, where the trees originate, they’re about to become more popular because they may lead miners to gold.

In Australia’s dry climate, eucalypts send roots down hundreds of feet looking for water.

In gold mining areas, scientists have found microscopic gold flakes, thinner than a human hair, in the tissues of their leaves and on the waxy residue that coats them.

They wondered if blowing dust could have carried gold particles onto the trees or if perhaps their deep roots could have drawn up trace amounts from far below the surface.

They conducted experiments, growing eucalypts in sterile environments, giving them gold-laced water. And sure enough, gold appeared in the foliage.

They realized that the gold is probably toxic to the trees, which send it out to their leaves where it can be shed.

The scientists analyzed eucalyptus trees in other parts of Australia but found very little gold. Clearly, trees in gold-rich regions were mining it themselves!

Before we get too excited about processing eucalyptus leaves for gold, it would take 100 trees to produce enough for a wedding band.

Scientists do believe, however, that searching for trace amounts in eucalyptus leaves could be a low-impact way of prospecting for gold in the future.