Oregon Honey Fungus Spans 9.6 Square Kilometers, Challenging for Earth's Largest Organism
Updated
Updated · spacedaily.com · Jun 14
Oregon Honey Fungus Spans 9.6 Square Kilometers, Challenging for Earth's Largest Organism
2 articles · Updated · spacedaily.com · Jun 14
Summary
Malheur National Forest’s Armillaria ostoyae covers about 2,385 acres—roughly 9.6 square kilometers—making it one of the strongest contenders for Earth’s largest single living organism.
Genetic tests confirmed the patch is one individual, not multiple colonies, after Forest Service researchers mapped the fungus in a 2003 study as the largest of several distinct Armillaria patches in the area.
Underground, the fungus spreads as mycelium and root-like rhizomorphs, moving tree to tree through roots and leaving clusters of dead or dying trees as visible markers of its reach.
Age estimates range from about 1,900 to 8,650 years based on spread rates of roughly 20 centimeters to 1 meter a year, while weight estimates stretching to 35,000 tonnes remain highly uncertain.
Its 'largest' claim depends on definition and metric: a seagrass clone in Shark Bay spans more than 180 square kilometers, while Utah’s Pando aspen clone is often cited as the heaviest known organism.