Recently, I came across an article on BBC Earth about the largest living organism on Earth. This story caught my attention because I have always assumed it would be a tree. The largest tree in the world is the General Sherman sequoia located in Sequoia National Park in California. It has a height of 83.8 meters and an estimate volume of 1487 cubic meters. However, even this giant is dwarfed by the true “alpha”. Little did I know that instead of looking up, I should have been looking down.
A specific honey fungus measuring 2.4 miles (3.8 km) across in the Blue Mountains in Oregon is thought to be the largest living organism on Earth. [The parasitic fungus colonizes and kills a variety of trees and woody plants.]…
They identified affected areas in aerial photographs and collected root samples from 112 dead and dying trees, mostly firs. Tests showed all but four of the trees had been infected with the honey fungus Armillaria solidipes (previously known as Armillaria ostoyae).
When mycelia from genetically identical A. solidipes meet, they can fuse to form one individual. The researchers harnessed this ability, growing fungi samples in pairs in petri dishes. By observing which ones fused and which ones rejected each other, they found that 61 of the trees had been struck down by the same clonal colony – individuals with identical genetic make-up that all originated from one organism.
The most widely-spaced were 2.4 miles (3.8 km) apart. The team calculated that the A. solidipes covered an area of 3.7 sq miles (9.6 sq km), and was somewhere between 1,900 and 8,650 years old …
Biologists have long debated what constitutes an individual organism. The record-breaking A. solidipes clonal colony passes the test based on a definition of being made up of genetically identical cells that can communicate, and that have a common purpose or can at least coordinate themselves. (British Broadcasting Corporation)
British Broadcasting Corporation. The largest living thing on Earth is a humongous fungus. November 7 2014. < http://www.bbc.com/earth/story/20141114-the-biggest-organism-in-the-world>