Cornell Mushroom Blog

A post by Kathie Hodge on a local mystery of mycology.

Many fungi are not known. Maybe they’ve never been seen before; maybe they got lumped in with something they resemble. We think there are a lot of them, and that we’ve recognized and named only 5% of the species that exist. It’s not hard at all to find an undescribed fungal species, though it is very hard to be sure you’ve got one. To do so requires you to know that it’s different from all the fungi we DO know, and this is a surprisingly difficult task.

There are known knowns; there are things we know we know.
We also know there are known unknowns; that is to say, we know there are some things we do not know.
But there are also unknown unknowns – the ones we don’t know we don’t know.

United States Secretary of Defense, Donald Rumsfeld, 2002

We tend to think that if a fungus has a name, it is known. But many fungi that have names are hardly known at all. Take Inocybe olpidiocystis, a fungus that has a name, but about which we know very little indeed. In fact hardly anyone has even mentioned this mushroom since it was described in 1918.

My predecessor George F. Atkinson was the first to describe this fungus, so it bears the name he gave it, along with Atkinson’s own name: Inocybe olpidiocystis G.F. Atk. The mushrooms grew in 1902 on Andrew D. White’s lawn– he was the first President of Cornell University. His house still stands in the center of Cornell’s handsome campus.

The grounds of the President’s house in 1902 looked much like the grounds today. Might these mushrooms still grow there, after more than a century? Are those mycologists lolling on the lawn? Our president doesn’t live there anymore, but the A.D. White House is host to meetings and galas; visiting scholars worry their palimpsests upstairs. In the parlor recently, I stood in the footsteps of Yankee Civil War General and 18th President of the United States, Ulysses S. Grant. Oaks and gardens still grace the grassy grounds atop Breezy Knoll. Those grounds haven’t been unmolested: Gardens and trees have come and gone, and a busy campus has risen up around this small oasis. In 1969 a crew of avant garde Earth Artists dug up the place and sculpted soil artistically in the downstairs rooms of the house–soil that might have hosted the mycelium of a known but unknown species.

Inocybe olpidiocystis was formally described in 1918, in a terse paper presumably completed by a friend after Atkinson’s unexpected death. The dried specimen in our herbarium is complemented by his notes describing the freshly picked mushrooms, but he did not photograph them, as he did so many others. To me its habit of growing low in grass, its sticky caps, and its fat stems recall Hebeloma crustuliniforme, a mushroom known as Poison Pie. And look at Atkinson’s charming drawing: this mushroom, like many Inocybes, has smooth ellipsoid spores and stout microscopic cystidia that bristle among the basidia on gill faces and gill edges. Each cystidium wears a crown of delicate crystals.

I’m no Inocybe taxonomist, so I wrote Dr. Brandon Matheny, North America’s foremost expert on Inocybe, a whole genus of abominable LBMs with a sprinkling of pretty and colorful things thrown in as balm to the beleaguered taxonomist. Brandon had never found this species, but he told me of a possible record of it from Florida, and a color photo of it in the 1985 Field Guide to Southern Mushrooms. I have reproduced that photo here, because I know you’re scribbling this fungus onto your wishlist and you need a search image. However, whether this photo actually represents Atkinson’s I. olpidiocystis or some other damnably similar Inocybe is an open question.

It is tempting to post WANTED signs on the walls of the A.D. White House, hoping someone will stumble across this elusive mushroom so we can rediscover it, and learn how it lives. Alas, the mushroom is what is known in mycological parlance as a Little Brown Mushroom, or LBM. Many otherwise courageous mycologists are afraid of LBMs, knowing they will likely struggle mightily to identify them, only to get stuck. In fact, this LBM no-man’s-land is likely home to many known unknown species. Our friend Inocybe olpidiocystis has been known for a century, and yet it’s still little more than a known unknown.

As for the unknown unknowns of fungi, I can only say that I feel sure there are many of them. The pace at which we are currently converting unknown unknowns to known knowns is delightfully staggering, yet we still have so far to go. That makes the study of fungi a fascinating and satisfying pursuit.

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