The Humongous Fungus is Among Us
—Taro Ietaka, Director of Conservation & Land Stewardship
Usually, when you think of nature's extremes - the fastest, the strongest, the most deadly - you think they must occur in faraway, exotic places, like cheetahs in the African savannas. However, here in the Northeast, we do have our representatives. One of them is the peregrine falcon, the fastest animal on Earth, which can be seen right here in Rye or among the skyscrapers in Manhattan. We also have a very close relative of the biggest organism on earth. This is not one that would immediately spring to mind: it is not a charismatic blue whale or giant sequoia tree. It is the "Humongous Fungus."
The Humongous Fungus is not a single mushroom the size of a tank. It is a network of fungal mycelium - the white cottony stuff you find when you roll over a log. Several years ago in Oregon, a single mycelial mat was found that covered over 2,400 acres - that is 1,818 football fields. It was given the name Humongous Fungus and declared to be the largest organism in the world (although botanists claim a clonal grove of quaking aspen trees growing in Utah may be larger).
Armillaria ostoyae, the honey mushroom (photo: Jerzy Opiola)
The Humongous Fungus is a type of honey mushroom - named for the color of its cap - and given the scientific name Armillaria ostoyae. We may have Armillaria ostoyae growing here in Rye (it has been found as close as Tenafly, NJ), however it prefers to grow in conifer forests, not the hardwood groves we have here. However, we do have its close relatives, also called honey mushrooms, Armillaria mellea and Armillaria tabescens, here at the Rye Nature Center. That is not necessarily a good thing.
Armillarias are deadly tree parasites that cause root and butt rot and can kill acres of forest. Here at the Rye Nature Center, we have found dying trees that have classic Armillaria 'shoestrings' beneath their bark. Armillaria forms flat black rhizomorphs that secrete digestive enzymes and then absorb decomposing tree matter, killing trees in the process. These rhizomorphs may be the legendary 'foxfire' that causes wood to glow in the dark, although I have never been able to witness this myself.
What can be done to stop the spread of this fungus so we don't become host for the next Humongous Fungus? One control measure is to encourage the growth of different, less-aggressive fungi, such as the oyster and sulfur tuft mushrooms, to act as competitors and keep the honey mushroom in check. Another way to approach the situation is to change one's outlook. Some mycologists view the honey mushroom as a fungal equivalent to a lion - thinning the herd of the weak and sick and ensuring the overall health of the group. At the Rye Nature Center we will do both.
