Despite the well-known statement "money doesn't grow on trees", it appears this phrase might not be 100 percent accurate after all. While paper money and coins may not fall off branches, it appears some tree leafs do reportedly contain gold embedded within them.
Is Gold ‘Growing’ on Trees in Australia?
Well, not exactly, but some findings made by researchers a few years ago is interesting. In 2013 scientists in Australia had reported they found very small particles of gold hidden inside the leaves, twigs and bark of eucalyptus trees. At the time, this discovery was well reported in the media.
It seems over time, the trees that were studied had been pulling up the pieces of the precious metal from the soil through their roots. The scientists, from the Commonwealth Scientific and Industrial Research Organisation (CSIRO), found the trees shining with gold in Kalgoorlie, a place where a major gold rush took place during the late 19th and early 20th centuries.
Photo description on Wikimedia Commons: "A goldminer who cycled a round trip of 1000 miles to a gold rush in Western Australia in 1895"
The quantities scientists found are microscopic and visible only through advanced x-ray imaging. Researchers discovered the trees were able to pull up the gold pieces from about 100 feet (30 meters) below ground. This provided some evidence that trees do not just absorb minerals from surface soil deposits, but go further down.
Gold is believed to be toxic to trees and pushing it from the roots out to the leaves appears to be the tree’s method of ridding it since leaves will fall off and decompose, starting the cycle all over again.
"The eucalypt acts as a hydraulic pump -- its roots extend tens of metres into the ground and draw up water containing the gold," said Mel Lintern, a geochemist, said in a press release. "As the gold is likely to be toxic to the plant, it's moved to the leaves and branches where it can be released or shed to the ground." 
Earlier research showed that trees will pull up any gold placed by man in the vicinity, but these amounts were in much larger quantity than what was occurring in the ground naturally. The 2013 research showed that trees naturally pulled the precious metal in.
19th and 20th Century Gold Rushes
Back in the late 19th century and early 20th century, Western Australia was the region of several major gold rushes. The discovery of the precious metal occurred in the Kalgoorlie, Coolgardie and Murchison regions, to name a few, in the 1890s and grew to become some of the most prominent mines in the century as people flocked to these areas.
Locations of a few of the major gold discoveries in Western Australia made during the late 18th century.
Kalgoorlie WA 6430, Australia
Murchison WA 6630, Australia
Coolgardie WA 6429, Australia
What started out as “lonely clusters” of tents and sheds eventually grew into booming towns that resulted in grand hotels, commercial businesses, schools and churches being built. The Golden Pipeline was started in 1898 and was completed in 1903, making fresh running water was available as well to the newly established towns. After the rush, the population in these towns declined, but the history and some of the structures remain. Visiting the tourism websites for these regions highlight that people can explore the regions where these historic rushes took place. , 
Photo description on Wikimedia Commons: "All that is left of the gold rush town of Burtville." Author notes the photo was taken in 2008 during a history tour.
Where is the Gold?
With this 2013 find, it is believed additional deposits of gold might be able to be located. However, it is not in any great quantity, so experts say not to expect a newly invigorated wild gold rush at this time. Currently, it would take gold remnants taken from several hundred trees to make even just a small piece of jewelry. According to a 2013 article in the Los Angeles Times, researchers found 80 parts per billion in the leaves, 44 parts per billion in the twigs and only four parts per billion in the tree bark. 
"We've done a calculation, and found that we need 500 trees growing over a gold deposit to have enough gold in the trees themselves to make a gold ring," said Dr. Lintern, reported BBC News at the time. 
So while there really isn’t riches “growing” on trees, there is hope though that this process researchers used could help shed some light on where to actually find gold deposits, which is good news for prospectors. Historically, 174,000 tons of gold have been extracted from Earth, said the World Gold Council, and there are estimates about 51,000 tons remain. According to National Geographic, over the past 10 years gold discoveries declined about 45 percent. 
Armed with new knowledge, experts might be able to try to pinpoint underground gold reservoirs in Australia or in other parts of the world. This would cause less disruption in the environment from mining activities if specific locations could be identified. Scientists also hope the method they used to find the gold in the trees can be used to locate other types of minerals as well, including iron, lead and copper.
Could some of the remaining gold be present in Western Australia? Time will tell.
The full report from the Commonwealth Scientific and Industrial Research Organisation was published on Oct. 22, 2013 and can be read online in the journal Nature Communications. 
[ Related Reading: The Kalgoorlie-Boulder Super Pit Gold Mine in Western Australia ]