Feature Article - for release the week of August 27, 2006

Dan Culbert - Extension Horticulture Agent

Mushrooms, Toadstools and fairy rings

A recent phone call to our office suggested that I write a column about collecting wild edible mushrooms.  Our drier than normal summer weather has recently turned wet.  Now is the time to see these amazing organisms to pop up in Florida Yards.  However, please DON’T pick the mushrooms, or consider adding them to your dinner plate, as many are poisonous.

Master Gardeners and Horticulture Agents have a few rules that should never be broken, such as read the label, use research-based  recommendations, and one more that relates to today’s topic: NEVER tell anyone that a mushroom is edible.  It’s not that there are delicious wild mushrooms out there.  There are just too many that can make you sick or even kill you. Mushroom identification must be done by experts with lots of experience.

One such expert is Wakulla County Master Gardener Bill Petty.  Today’s column is adapted from an article written by Bill.  He’s an expert, has published articles in the Mushroom Journal and maintains a website, Florida Fungi.  I have adapted his article for local use.

Know your mushrooms

First and foremost, DO NOT EAT WILD MUSHROOMS unless you are ABSOLUTELY sure you have identified the mushroom correctly and KNOW that it is edible. Many common mushrooms are poisonous, and a brief newspaper article cannot give enough information to allow you to identify edibles with certainty.

Mushroom identification is not a casual affair: you must acquire several good field guides, and regularly go out to collect and identify them.  Then, maybe in a few years, you will have enough confidence to know that fungi.

The beautiful white Destroying Angel mushroom (Amanita virosa) is deadly poisonous, but it is related to an edible species.  Since the deadly one is common in our area, leave any suspect mushroom in the ground.  Study the genus Amanita well, and do not eat any from that group until you have studied it for several years.

Better yet, consult an expert to confirm your identification of this mushroom.  If you do decide to try eating wild mushrooms, only try one species at a time.  And be sure to save a whole mushroom of any that you eat in case the poison control center needs an example to identify. Your local County Extension office can also send photos or actual specimens for Identification.  Here in Florida we use the services of retired UF/IFAS Mycologist Dr. James Kimbrough, who can help identify Florida mushrooms.

Lawn Mushrooms

As to lawn damage by mushrooms, they rarely cause landscape problems.  Most lawn mushrooms are fungi that feed on decomposing grass clippings.  Sometimes mulch that is kept too wet can also host a crop of these decomposers.

Rather than trying to kill mushrooms by using expensive fungicides, enjoy their beauty and toss them in the compost pile once they are past their prime. [Note from Dan:  Don't compost mushrooms that are poisonous or those known to cause lawn and landscape diseases!]  If you don't like their looks, you can always mow them down, but they will keep coming back.  Another trick is to reduce the amount of water added to the landscape, which will discourage their growth.

The most common lawn mushroom is the green-gilled Lepiota.  Also known as the Parasol or Fairy ring mushroom, the scientific name was changed to Chlorophyllum molybdites about thirty years ago.  (The name Lepiota morgani appears in old books or posters).  These are large whitish mushrooms (four or five inches across the cap) with reddish-tan scales on the cap. The center of the cap will have dense scales, which become sparser toward the edge. The stem is three to five inches long, with a ring (annulus) around it near the top.  The ring is easy to move up and down the stalk, and the cap breaks easily from the stem.

To be certain of mushroom identification, scientists make spore prints. Place the cap on a piece of white paper and cover it with an up-side down bowl for a few hours. Dust-like spores will fall from the gills onto the paper, leaving a print that looks like the underside of the mushroom’s gills. Wash your hands well after handling. After the print is thoroughly dry, it can be sprayed with a clear lacquer and framed

If the color of the spore print is a light grayish-green, chances are good those local lawn mushrooms are the poisonous fairy ring mushroom.  Do not eat even one bite or you will be sick (at both ends) for three days!   I know of no deaths as a result of eating this mushroom, but it does cause severe gastrointestinal upset. [Note from Dan: fatal reports of pets eating these mushrooms do exist!]

Toadstools & Fairy Rings 

The term toadstool is thought to indicate that mushrooms are poisonous, but there are instances of certain edible mushrooms are called toadstools.  And besides, few toadstools could hold a hefty Buffo toad.  

Fairy Rings are another term associated with mushrooms.  Often lawn fungi erupt in a circular pattern as a result of an ever widening ring of these soil-based fungi.  There is folklore associated with Fairy rings, with predictions of either dire consequences or good luck.  

Golf course attendants don’t like Fairy rings.  Not only do the mushrooms present an obstacle to the rolling golf ball, but the ring can also show either a circular pattern of dark green very thick growth or a circle of dead grass.  There are fungicides (e.g. Heritage^TM) that can suppress fairy rings, but they are expensive.  

Cultivated Mushrooms

The common edible mushroom does not grow in the wild; it comes only from special controlled environment grow houses.  There are a number of other specialty mushrooms that are found in the produce section of the supermarket.  For example, the Shitake mushroom is cultivated in areas of Florida that have the right kind of hardwood logs to support its production. 

There are some edible wild mushrooms out there, but unless you take the time to study them carefully, that special meal may be followed to a trip to the hospital if the wrong ones are consumed.  I recommend Bill Petty’s website, Florida Fungi, or Dr. Kimbrough’s book, Common Florida Mushrooms, if you want to learn more about these natural treasures from your Florida Yard.

I’ve placed more information on our Okeechobee web page, http://okeechobee.ifas.ufl.edu.  If you need additional information on wild or lawn mushrooms, please email YOUR LOCAL extension office; check this website for contact information: http://solutionsforyourlife.ifas.ufl.edu/map/ .  Those living in Okeechobee can contact us us at okeechobee@ifas.ufl.edu or call us at 863-763-6469.  Local residents can stop by our office at 458 Hwy 98 North in Okeechobee, and visit our Okeechobee County Master Gardeners.

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Trade names, where used, are given for the purpose of providing specific information. They do not constitute an endorsement or guarantee of products named, nor does it imply criticism of products not named. The Florida Cooperative Extension Service - Institute of Food and Agricultural Sciences is an equal opportunity/affirmative action employer authorized to provide research, educational information, and other services to individuals and institutions that function without regard to race, color, sex, age, handicap, or national origin.  Florida Cooperative Extension Service / IFAS /University of Florida.  Millie Ferrer, Interim Dean Last update: 07/11/2011 .  This page is maintained by Dan Culbert 

references

Culbert, D.F. "Fairy Rings".  Vero Beach: Press Journal, October 5, 1997.

Datnoff, Lawrence E. and Cisar, John L. Preliminary Observations On Fairy Ring Control.  Fort Lauderdale: UF/IFAS REC, 3/15/07. http://flrec.ifas.ufl.edu/pdfs/FairyRingControl.pdf. 

Elliott, M. L. and Simone, G. W. Fairy Rings SS-PLP-07.  Gainesville: UF/IFAS Extension Service, April 2001. http://edis.ifas.ufl.edu/LH046

Garofalo, Joe. "What’s growing in my landscape mulch?" In PROSCAPES Newsletter.  Homestead: Miami/Dade Extension Service, July-Sept, 2003, p 5-6. 

Kimbrough, James W. Common Florida Mushrooms SP-256.  Gainesville: UF/IFAS Extension Bookstore, 2000. 

Petty, Bill. Summer Mushrooms. Tallahassee: UF/IFAS Leon County Extension Service, July 25, 2002. http://leon.ifas.ufl.edu/News_Columns/2002/072502.pdf 

Stephens, James M.  Mushroom -- Agaricus bisporus HS628   http://edis.ifas.ufl.edu/MV095