Fairways, Fields and Fungi

Drs. George Barron and Tom Hsiang

Department of Environmental Biology, University of Guelph

(Versions of this article were published in 1999 in Golf Course Management volume 67 issue 12 pages 58-61 and GreenMaster volume 34 issue 5 pages 10-16)

Most mushrooms are soft, delicate and sensitive to drying, and they don't care for exposed habitats. They prefer the deep, dark recesses of the forest. In the woods, there is abundant organic debris they can use for food, and it stays damp for long periods under the canopy. Fungi like it wet!. Wide open grassy places exposed to the sun all day, therefore, are not amongst the favourite spots for fungi to set up shop. There are of course exceptions to every generalization and not unexpectedly, therefore, a handful of fungi have adapted to the more rigorous demands of the open spaces. From time to time often following prolonged periods of intermittent rain and somewhat cooler weather, mushrooms will pop up in abundance over lawns, fields and fairways.

Over the years, thatch builds up under the grass in fairways and other grassy places. The organic matter mixed into soil provides an ideal substrate for a host of microorganisms including fungi. Not only does it supply the food source (cellulose, etc.) for energy, but the thatch tends to hold the moisture for longer, which is ideal for fungus growth. As well as thatch, some turf fungi also grow on dead wood. This source becomes available when trees die, and the stumps and hidden roots under the turf supply abundant food for a long time for wood decay fungi such as Mica Cap

To eat or not to eat!

Periodic abundance of mushrooms on golf course might attract the eye, but don't go running willy nilly around the golf course harvesting mushrooms. While golf courses are often a good place to spot mushrooms, they are, nevertheless, a dangerous place to collect them for eating, and this practice is not recommended. Golf course protocols require a number of sprays over the season particularly during wet years when diseases and fungi are more prevalent. So, have a care as a delicate coating of pesticide may coat your potential breakfast.

What are mushrooms?

The active fungus is a very fine thread measured in microns (1 micron = 1/1000 mm). It colonizes the thatch or buried wood. When times are right, the fungus produces the fruitbodies that we call mushrooms. Mushrooms are amongst Mother Nature's most prolific, sophisticated and successful spore-producing machines. A good-sized mushroom can shoot off a hundred million spores an hour for days on end. Even the smallest of the lawn mushrooms shoots off spores by the million. These are carried by capricious winds to other sites for further growth. The following mushrooms are commonly found in open grassy areas.

Mica Cap (Coprinus micaceus, Figure 1)

This is probably one of the most common and widespread of the lawn mushrooms. It grows in old hardwood stumps, dead roots and buried wood. It produces mushrooms early in the year, usually in large clusters in grass or soil above the buried wood. The caps are small, tan coloured, radially streaked and when young covered with a layer of tiny mica-like particles that glisten in the morning sum, hence the common name. These delicate flakes often disappear with rain or ageing. This species is edible but the mushrooms are flimsy and will disappear to almost nothing during cooking. Not only that, there are not any rave reports about its flavour!

Haymaker's Mushroom (Panaeolina foenisecii, Figure 2).

Perhaps the most common of the lawn mushrooms, this species comes up early in the year scattered or in small groups. It is recognized by its small, hemispherical cap and mottled gills. The caps often change colour from darkish brown to light tan as they dry. The spores are black and will leave black smudges on the fingers if the gills are handled. This small mushroom is only one to three centimetres in diameter. It is reported as poisonous because it contains very small amounts of the hallucinogenic psilocybin chemical.

Agrocybe (Agrocybe vervacti, Figure 3)

Locally common near the Great Lakes but not as well known elsewhere, this is a distinctive yellow-brown mushroom. The caps are up to 4 cm across. It produces mushrooms during wet periods in summer. Edibility is unknown and no one has volunteered to test it.

Fairy Ring Mushroom (Marasmius oreades, Figure 4)

The word "choice" is often overused and overstated for wild edibles of all types. Have you ever chewed on dandelion leaves! For the most part wild mushrooms aren't as flavourful as the gourmets tell us. The Fairy Ring Fungus, however, is an exception and is one of the better tasting edible mushrooms. This knowledge won't do you a lot of good in Ontario, however, as the Fairy Ring fungus is not that common in this province. In the west, on the other hand, Marasmius oreades is abundant and is also a serious problem and very destructive of turf grasses. It produces mushrooms in rings hence the common name. More important in dry weather it shrivels up but with heavy dew or during rainy weather it resurrects itself and starts to produce spores. You can collect this fungus wet or dry and shrivelled up. If it is dry and it is put in water, it will flesh out and look just like "new". If it doesn't do this you've made a mistake and it isn't the Fairy Ring Mushroom!

Shaggy Mane (Coprinus comatus, Figure 5)

Shaggy Mane is one of the "Inky Cap" group. In this group the caps break down rapidly by self digestion (autolysis) to an inky black fluid. Shaggy Mane is a medium sized mushroom that is easily recognized by its tall scaly cap. It is highly prized as an edible by some, but it ripens very rapidly to a black inky goo and must be eaten the day it is collected or you will have to suck it through a straw. Shaggy Mane is more common in late fall and more prolific on disturbed sites where it colonizes woody debris.

Tippler's Bane (Coprinus atramentarius, Figure 6)

This mushroom is conical to bell-shaped and has a smooth, silky, streaked cap with a metallic grey sheen. This inky cap is edible but with a caution. Alcohol must not be consumed with the mushroom or for several days after. The caps contain a substance called coprine which acts like antabuse and, in association with alcohol, gives most unpleasant (but not lethal) symptoms such as flushing over the upper body, metallic taste on the mouth, nausea etc. It produces mushrooms in summer and fall.

Dunce Cap (Conocybe lactea, Figure 7)

This species is only a few centimetres across at best. It is recognized by the whitish to pale tan, conical cap and the gills that turn reddish brown as the spores mature. It is quite common and produces solitary mushrooms or in scattered groups in early summer.

Smooth Lepiota (Leucoagaricus naucina, Figure 8)

One of the larger "grass" mushrooms, the Smooth Lepiota can be up to 10 cm across or more. The cap is hemispherical to convex with a central knob. The gills are white at first but become pale pinkish in age. The stalk is stout and swollen at the base and has a narrow ring. This edible species is never recommended because it is very similar to the deadly poisonous Destroying Angel which has already killed a number of Canadians over the years. It produces mushrooms in summer and fall and is especially common on newly developed grassy areas.

Sidewalk Mushroom (Not illustrated) (Agaricus edulis)

This medium-sized fleshy mushroom is related to the meadow mushroom ( Agaricus campestris) and the cultivated mushroom (Agaricus brunnescens) which you can find commonly at the supermarket. All three are very similar in shape, size and general appearance. When young the gills are pinkish but rapidly turn to a dark chocolate brown and even blackish brown. The stalk is stout with a well developed ring. It grows in or near hard-packed ground such as cart paths. It is reported as edible and very good and will be very similar in flavour (but better!) than its commercially produced cousin.

Next time you're wandering around a golf course or sports field and it's a slow day keep your eye open for one or other of these common mushrooms. You don't have to eat them! You can enjoy them as one of nature's little wonders. If the worst comes to the worst you can always practice your swing on a Conocybe or a Panaeolina and impress your friends with your knowledge of the names. Sadly for some, the hallucinogenic mushrooms of the Psilocybe genus (magic mushrooms) that are so common on the east and west coasts do not seem to thrive in the central regions. C'est la vie!

If you're really excited about all this, there is a new book on mushrooms just published (Barron, 1999). Other useful guides to mushrooms of North America include Lincoff (1981), McKnight & McKnight (1987), and Miller (1978). By the way, we thank Brian Shelton for the fine pictures of Tippler's Bane, and the Smooth Lepiota.


Barron, G.L. 1999. Mushrooms of Northeast North America. Lone Pine Publ., Edmonton, Canada. See http://www.uoguelph.ca/~gbarron.

Lincoff, G.H. 1981. National Audubon Society Field Guide to North American Mushrooms. Knopf, New York.

McKnight, K.H. and V.B. McKnight. 1987. A Field Guide to Mushrooms of North America. Peterson Field Guide Series, Houghton Mifflin, Boston.

Miller, O.K. 1978. Mushrooms of North America. Dutton, New York.