Humongous fungus: ancient invaders of old-growth forests

December 12, 2018 1:47 PM

In 1992, Anderson and his colleagues estimated that the honey mushroom, which is growing in a forest on Michigan's Upper Peninsula, was 1,500 years old, weighed 100,000 kilograms (~220,460 pounds or ~110 tons) and covered 15 hectares (~37 acres). Based on additional samples taken between 2015 and 2017, the new estimate is that this mushroom is at least 2,500 years old, weighs 400,000 kilograms (881,849 lb or ~441 tons) and covers about 70 hectares (~173 acres) (Phys.org). According to the researchers, "any temporally continuous forest could support large , old Armillaria individuals," and this isn't the biggest, or oldest (BBC; previously). Worse, Armillaria doesn't share well, and tends to kill off trees. The Secrets of the 'Humongous Fungus' (The Atlantic).
posted by filthy light thief (10 comments total)

Hunting and cooking honey mushrooms, armillaria mellea and armillaria gallica (Forager Chef)

Honey mushrooms are one of the best fall mushrooms I’ve eaten. If the conditions are right, you could walk out of your favorite patch of woods with a literal truckload of these, it’s all about timing though. When I describe them to people who want to start picking them, I usually say something to the tune of “lookout for patches of mushrooms that grow like an infection”. Honeys are a parasitic mushroom, infecting trees and whole swaths of woods. Even when they’re not fruiting, you can be on the lookout for areas they might like, my favorite variety grows on oaks, so I look for forests with hardwoods filled with dead and dying wood.

Emphasis original, and the chef is not far off.

“People don’t think of mushrooms killing trees,” said Greg Filip, a pathologist with the U.S. Forest Service.

Trees often benefit from mushrooms at their roots. Honey mushrooms, however, suck the life out of a number of types of trees.

Filip stands in the Malheur National Forest surrounded by trees dying in slow motion.

“It could be 20, 30, 50 years maybe before it finally dies,” he said.
...
If you’re thinking of a classic mushroom with a cap and gills and spores, the honey mushroom fits that bill for only a few weeks each autumn.

Most of the year it’s just a thin, white layer that packs a lethal punch.

Filip chops at the base of a tree with a hand axe, moving higher and higher up to remove the bark. Even two feet above the roots, he finds a layer of the white fungus.

His fingers peel back a layer that feels “like latex paint.”

That white fungus spreads up under the tree’s bark and rots its roots.

“Then there’s no movement of water or nutrients up and down the tree when that happens,” he said.

Michigan's humongous fungus was mentioned previously, and Crystal Falls, Michigan celebrates its local celebrity at the Humongous Fungust Fest, where

For three days, you can enjoy the Fungus Fest Parade, the Toadstool Tournament (softball), a Strongman Competition, a giant pizza, a mushroom cook off, and so much more.

posted by filthy light thief at 1:52 PM on December 12, 2018

So you could say... there is humongous fungus... among us?
posted by Homo neanderthalensis at 2:07 PM on December 12, 2018 [2 favorites]

All this needs to be the next SF blockbuster are tall blue people.
posted by seanmpuckett at 2:46 PM on December 12, 2018

A bad year for honey mushrooms is a good year for trees.

That said, the trees have friends...sort of: it's parasites all the way down.
posted by Laetiporus at 3:26 PM on December 12, 2018 [1 favorite]

Nature always needs to be weirder than I could possibly have imagined. I am in favor of this mushroom.
posted by philip-random at 4:25 PM on December 12, 2018

I "am sure" I know it as the "honeycap mushroom" but the internet does not support that at all. Can anyone confirm this or am I suffering from mushroom poisoning?
posted by sjswitzer at 7:41 PM on December 12, 2018

From my random internet readings, I didn't see it listed as the honeycap mushroom, just honey mushroom (and there's not one specific "honey mushroom," the name seems to be applied across many/ most/ all of Armillaria).

How big is the Oregon humongous fungus, visually? Here's a map, from r/MapPorn, which includes a few more notably large colonies/ clone armies in the region.

Bonus biology link: Behemoth Seagrass Clones Among Earth's Oldest Organisms

Seagrass meadows can be composed of ancient giant clones, organisms stretching up to nearly 10 miles wide that may be up to tens of thousands of years old, scientists find.

The seagrass in question, Posidonia oceanica, reproduces either sexually through flowering or asexually by generating clones of itself. This can result in single organisms that are very large and very old.
...
To learn more about how long the seagrass P. oceanica can actually live, researchers analyzed 40 meadows of it across 2,175 miles (3,500 km) of the Mediterranean.

Not all of the seagrass the scientists discovered was genetically identical. However, the seagrass clones they did find suggest both extreme size and age. Some reached up to 9.3 miles (15 km) wide and may well be more than 100,000 years old.

posted by filthy light thief at 9:38 PM on December 12, 2018

Brain fart on my part, I was thinking of the candy cap mushroom. Completely different and more unambiguously edible.
posted by sjswitzer at 10:25 PM on December 12, 2018

I want to eat all of the mushrooms. How do I buy consumable honey mushrooms? Maybe it's time for an ask.metafilter question...
posted by Grither at 7:00 AM on December 13, 2018

MetaFilter: Brain fart on my part.
posted by homunculus at 8:48 AM on December 14, 2018