As kids, most of us learned that at 110 feet long
and up to 100 tons, the
blue whale is the largest thing
that ever lived. Later, many of us later found out that
giant sequoias dwarf the largest blue
whale, towering 275 feet tall and weighing in at 1,385 tons.
These examples of Armillaria
Ostoyae are identical to the mushrooms formed by what
might be the world's largest organism.
© Tom Volk
Now, imagine an Earthly organism that is measured in miles
and acres! Armillaria ostoyae, popularly known as
the honey mushroom, currently holds the title for largest
living thing. Its stats?
Width = 3.5 miles across
Area = 2,200 acres
Weight = not yet calculated
How can that possibly be? Armillaria ostoyae is a
fungus that kills trees. In 1998, Catherine Parks, a
scientist at the Pacific Northwest Research Station in
La Grande, Oregon, heard about a big tree die-off in the
forest east of Prairie City, Oregon. The trees were dying
from root rot, a disease caused by this fungus. Scientists
took aerial photographs of the affected area to determine
its extent, then took samples from the roots of diseased
trees. DNA tests showed that all of the samples came
from one huge individual that had been feasting on trees
in this area for perhaps 2,400 years. Most of the mass
of this humongous fungus is underground, which makes it
hard to detect and likely that there are even larger
ones we have not yet discovered.
© 2001 American Museum of Natural History