Mushroom Hunting: The Serious Side of Mushrooming

By Tom Nauman

Morels have returned! The first reports to the Sightings Page on the net at were from California on March Third. Last year the first report was on March 9 from Virginia. Does this mean an earlier season? Probably not. Since we didn't have any reports from California last year, it is difficult to predict.

One prediction we can make about this season is that the quantity of ground moisture we've had since December should help the crop provided the weather doesn't get too hot too fast like last year.

I just received my copy of McIlvainea containing Ken Cochran's annual report of The Mushroom Poisoning Case Registry for the year 1999 from The North American Mycological Association (NAMA). It's always an interesting report and can be viewed online at

Reporting is voluntary so there may be more unknown cases. For 1999, there were 108 cases reported involving 105 humans and 3 dogs. Two of the human cases were fatal! The first in New York involved a poisonous species that the victim had mixed with two edible species. The other in New Jersey was believed to have been caused by ingesting several different poisonous mushrooms.

There were no reports from the Midwest. The reports came from 17 states with the most coming from: Colorado 38, California 10, Oregon 10, New Jersey 9, and Idaho 8. Of the 105 humans involved, 77 were adults age 16 or older.

Of particular interest is the species involved in the reports. Ken Cochran notes that when only a single case is associated with a given species, one should be cautious about blaming the mushroom. In other words, the mushroom may have been too old, not stored properly, or not cooked properly. Or, the habitat made an otherwise edible mushroom dangerous.

Such is the case with three cases involving Laetiporus sulphureus commonly called the Sulfur Shelf or Chicken Mushroom, which is usually considered a choice edible. Apparently the suspect mushroom had been harvested from a black locust stump. Black locust contains toxins which may have been absorbed by the mushroom. Mr. Cochran also notes that this particular mushroom has the reputation of being toxic when collected from eucalyptus trees in western states.

Two 15 year old males ingested Gyromitra esculenta which they believed to be morels. This particular mushroom is one of the seven similar species with a red cap and white stem that are commonly known as false morels. Gyromitra gigas is also a member of this group and was the cause of one case when it was consumed raw by one subject. Others that ate it cooked had no problems.

Another case of an otherwise choice edible being a problem occurred with Pleurotus ostreatus commonly known to as the oyster mushroom. In the particular case mentioned the victim had eaten the mushroom raw in a possible suicide attempt that only caused vomiting. There was even a case involving Morchella angusticeps (one of the black morels) causing vomiting when eaten raw by a commercial picker. Most experts that I know advise that wild mushrooms should never be eaten raw.

How safe are mushrooms? The discussion area of the report states that for the timeframe of 1993-1997 the Centers for Disease Control summary of food borne outbreaks listed 21 cases due to mushroom poisoning and 310 food cases for that same period. I've heard that one in 200 people is allergic to something.

NAMA's Mushroom Poisoning Case Registry is a tremendous public service and needs the public's help in gathering accurate information. Reports are welcome from anyone who has experienced, or consulted on, a mushroom poisoning case; and reports may sent by post- or e-mail, with forms available on the Registry's website or can be requested by phone [734-971-2552], e-mail []. or post-mail, 3556 Oakwood, Ann Arbor, MI 48104-5213. The NAMA website begins at

Remember, whenever you want to try eating a mushroom you're not familiar with, check it in at least two field guides. If they say it's edible, try just a nibble, wait 24 hours, and if there are no ill effects then consume larger amounts. All past articles are available Please feel free to contact us with questions or comments. Especially if you have ideas or suggestions for future columns: Tom and Vicky Nauman, Morel Mania, RR1 - Box 42, Magnolia, IL 61336, Phone 309-364-3319, Fax 309-364-2960,