Scientists have found gold in eucalyptus tree leaves. Well, they knew microscopic gold particles were in the tree leaves, but recent experiments prove that the gold came from the ground underneath instead of being blown in by the wind. Eucalyptus tree roots grow very deep, more than 130 feet in some cases, to access water. When they take up the water, gold particle leech up into the tree.
The researchers compared eucalyptus tree leaves at gold prospecting sites in Western Australia with leaves from trees 2,625 feet (800 meters) away. They also grew eucalyptus trees in greenhouses with potting soil dosed with gold particles, as well as in normal potting soil without gold.
What They Found
Leaves preferentially stored microscopic gold particles about eight micrometers wide on average. Study authors speculate the particles came from underground, seemingly taken up by the root system of the trees. About 20 leaves needed to be sampled to statistically reveal the presence of gold underneath the trees.
The leaves never contain a lot of gold, but the presence of any may indicate what spots contain gold underground, which is a lot easier than digging randomly to find it. Read more about eucalyptus gold at National Geographic News. -Thanks, Marilyn Terrell!
(Image credit: Bill Hatcher/National Geographic)