Fool’s Funnel (Clitocybe rivulosa)

All things are poisons, for there is nothing without poisonous qualities.  It is only the dose which makes a thing poison. – Paracelsus

This is a small, dull white mushroom that is widely distributed in North America and Great Britain.  It is about 1 – 2 inches tall with a 3/8 -1.5-inch-wide cap.  It has no distinctive taste or smell, but it is poisonous.  It is often found in grassy habitat.

It also is known as the sweating mushroom, not because of physical characteristics but due to the symptoms it causes for the unlucky person who mistakes it for similar fairy ring champion (Marasmius oreades).  The primary toxin is muscarine, which causes blurred vision, increased salivation excessive sweating, lacrimating (in pegnant females), bronchial secretions, abdominal cramping, increased gastric acid secretion, and diarrhea.  Death has been reported in 8 – 9 hours in 5% of cases but can be avoided with prompt treatment with atropine.    Be very, very careful.

The genus name Clitocybe – Latin for sloping head and rivulosa – Latin for river or stream, referencing the faint channels or annular ridges that form on mature caps of this mushroom.

This mushroom is similar to the non-poisonous fairy ring champion.  The gills are important for separating these two mushrooms.  The gills of the fairy ring champion are free of the stem as below:

Fairy ring champion

…. while the gills of the ivory funnel are decurrent, or run down the stem.   Both the poisonous and edible species can grow in a fairy ring pattern, adding to potential confusion.  I would suggest becoming more familiar with the mushrooms in your area before venturing out for dinner.   Many folks are wary of mushroom picking, for good reason.

Fairy ring pattern of growth

Their chief use, the writer thinks, is as condiments; and as a condiment that may poison the eater is an undesirable one, the conclusion is obvious.  Doubtless this writer’s advice will not appeal to those who regard the unculled mushroom crop as a vast neglected source of food supply for the million; but it is an undisputed fact that he who never eats a mushroom will never suffer from mushroom-poisoning.  The Fallacious Mushroom,  In: The Literary Digest, 1913,  Edward Jewitt Wheeler and Isaac Kaufman, eds.

Speaking of which, a good friend who shall remain nameless (Cheryl) would often go out with Michael the mushroom whisperer in search of prey.  They and a small group recently went out to see a great fungus movie – go see it if it is in your area –  Fantastic Fungi

Cheryl was so inspired by the film that she got home and started foraging around her neighborhood, finding quite a variety of ‘shrooms.   She took what she thought were fairy ring champions and fried them up in garlic and mushrooms for part of dinner.  She was on call that night in her health care job.  Before she had to go out she started getting hot, thinking it was an annoying hot flash.  Only if it were so (start Jaws music).

She started to sweat, and then salivate.   Oh-oh.  She went back to the mushroom guide and read the description of fairy ring champion again, turned the page and at the top it said “….and can often be confused with the sweating mushroom”.  Oh %$#&, #$%#!!  Stomach cramps ensured. 

A quick call to Poison Control confirmed she should get to the ER.  She often practiced in the closest hospital and wanted to save herself embarrassment of showing up as a self-poisoned patient, so went 25 minutes further to another hospital.  What could go wrong?

She and her barf pail arrived without (major) incident.  They hooked her to an IV and monitored her vitals for a few hours and wanted to check her in for observation overnight, but she went home, took a Benadryl and called it an evening.  All was well the next morning.  Cheryl got finger wags and a minor lecture from Michael the mushroom expert and several of us.   Don’t do this at home.

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