Spongiforma Squarepantsii, The Spongebob Mushroom

During the spring of 2011, three mushroom experts published their findings about a very unusual species of fungus from the rainforest of Borneo. The tropical mushroom forms a brilliant orange, resilient fruiting body that bounces back when you squish it. Dr. Dennis Desjardin, one of the co-discoverers, described the mushroom this way: “It’s really like a rubbery sponge with big hollow holes.”

Spongiforma squarepantsii, the Spongebob Mushroom
Spongiforma squarepantsii, Tom Bruns, U.C Berkeley Licensed under Creative Commons – Attribution Share Alike 3.0 Unported

Dr. Desjardin, Kabir Peay, and Thomas Bruns submitted a paper describing their new species to Mycologiathe academic journal of the Mycological Society of America. The co-authors dubbed their discovery Spongiforma squarepantsii, demonstrating yet again that some mycologists are fun-loving  pranksters.

Description of the Spongebob Mushroom

Spongiforma squarepantsii shares a good bit with its namesake, the venerable and much-beloved Nickelodeon star Spongebob Squarepants. First of all, the fruiting body is bright orange and spongy, and overall it has a cheerful appearance.

Another reason Spongiforma squarepantsii acquired its unusual Latin name is because its microscopic fertile surface is covered with what looks like tube-shaped coral. To some eyes, the spore-bearing bits of S. squarepantsii look just like Spongebob’s home at Bikini Bottom.

Spongebob Mushroom
Microscopic View of Spongebob Mushroom Mushroom Observer: Desjardin, Peay & Bruns Licensed under Creative Commons – Attribution ShareAlike 3.0 Unported

Mycologia hesitated to publish the article because of the name. They thought it was “too frivolous.” However, eventually the journal picked up the article a few months after Peay, Desjardin, and Bruns submitted the piece.

S. squarepantsii is one of only two species in the genus Spongiforma; the other is Spongiforma thailandica, and it was discovered in 2009 in Thailand (as the name suggests). These two mushrooms share a lot of characteristics with sea sponges. Both of these spongy-fungi can be wrung out and will spring back to their original shape once released. There are a number of fungi that look somewhat like the Spongiforma mushrooms, but the closest relatives to S. squarepantsii are…drumroll…Boletes!

Boletus, Spongebob Mushroom's Cousin
Boletus, Spongebob Mushroom’s Cousin
Anne Burgess
Licensed under Creative Commons – Attribution ShareAlike 2.5

Boletaceae are a family of fleshy fungi (see: mushrooms) that have a spongy layer underneath their caps rather than blade-like gills. They grow all over the world, but they look not a thing like S. squarepantsiior S. thailandica. The Spongiforma appear to be much closer kin to the Cauliflower Mushroom (Sparassis crispa) or a coral mushroom (Ramaria, one of the most maddeningly difficult genera to identify).

The genetic markers of S. squarepantsii show that it evolved from a bolete. I think it very likely that more Spongiforma species will be discovered in Indonesia, southeast Asia, and perhaps other places too in the years to come, and that will lend us new opportunities to learn about how the Boletaceae evolved.


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