Foraging Fun: Agaricus

If you have ever eaten mushrooms from a grocery store or restaurant, which includes 100% of us essentially, you have eaten an Agaricus mushroom. Agaricus is one of the more familiar of edible mushroom genera that has been utilized by people of different cultures throughout history that existed where ever this mushroom appeared in the wild. This familiarity and obsession eventually lead to cultivation, when one species, Agaricus bisporus, was selected to be ‘domesticated’ and ‘trained’ to exist within entirely artificial conditions and produce mushrooms at an unprecedented level.

Despite commercially mass produced mushrooms being available almost all the time and virtually where ever produce is sold, there are still those that are enthralled with the intuition and experience of hunting wild mushrooms as we undoubtedly did thousands of years back in our evolutionary history. Presumably through trial and error (an extremely dangerous practice no doubt) we managed to experiment, select and develop preferences for different species that we determined were not only safe but a pleasure to eat and combine with the flavors of other foods.

*above photo of a young horse mushroom (A. arvensis), my first of the 2014 season. Note the thin scales on the cap. These are not always present and are more common on some species than others, but are a diverse feature of most edible Agaricus mushrooms when present and can be a valuable identification feature to help separate them from potentially dangerous species. From my observations, the meadow mushroom (A. campestris) tends to have them less frequently than A. arvensis.

Before I go any further (I don’t really want to mention all of this, but I feel as if I should) I would like to remind you that eating wild mushrooms is dangerous and should only be attempted when identification is absolutely certain. Although there are only a few mushrooms found in Ontario and throughout Canada as a whole that will most likely kill you even if  a very small amount is consumed, the vast majority of ‘poisonous’ mushrooms will just make you extremely ill at the very worst, and you will recover from the side affects in a couple hours to a few days, respectively. Still, don’t do anything stupid and put yourself at risk unnecessarily. Lots of research and in-the-field experiences is required for you to develop the right skills to make accurate judgments, and there is absolutely nothing wrong with asking an expert or more experienced forager for guidance*. Also, always cook wild mushrooms throughly, because many perfectly delicious species can make you ill if consumed raw or undercooked.

With that out of the way, I would like to introduce you to some Agaricus mushroom species that I have come across over the last year or so and in the process explain some of the best ways of differentiating these mushrooms from other species that could really ruin your day or even send you to the hospitalsuch as those in the genus Amanita which includes some of the world’s deadliest species. From my observations, Agaricus mushrooms are in general quite common and you don’t need to go too much out of your way to find them. The majority of the edible or closely related species grow in open meadows, fields or lawns usually near or directly underneath a variety of different tree species including but not limited to ash (Fraxinus spp.) and pine (Pinus spp.). They seem to prefer part sun/shade or light shade, although I have heard of them appearing in entirely open habitats as well. Rich, well-drained soils with plenty of composted plant material or other light debris in extensive grassy areas that aren’t frequently cut in parks, along boulevards, adjacent to soccer fields or woodland edges are all suitable habitats where Agaricus mushrooms might show up.

Classic specimens of what I believe to be meadow mushrooms, A. campestris, in different growth stages. bright pink gills when immature, darkening to rose and finally maturing to a rich chocolate brown and a white stem and cap with thick flesh are all characteristic features of not only this but other edible Agaricus.
Classic specimens of the meadow mushroom (A. campestris) or a similar edible species, in different growth stages. bright pink gills when immature, darkening to rose and finally maturing to a rich chocolate brown and a white stem and cap with thick flesh are all characteristic features of not only this but other edible Agaricus. These individuals were found growing within a few yards of each other underneath a large ash (Fraxinus americana) tree in Hamilton last September a few days after a long cool rainy period.

The fruiting period for Agaricus mushrooms is conveniently quite long, although certain species have a tendency to fruit earlier or later than others. I have seen what may have been horse mushrooms (A. arvensis) fruiting in mid-June and meadow mushrooms (A. campestris) persistently producing mushrooms in late August and early September. It’s also a good idea (actually a great idea) to consider the environment that the mushrooms are growing in. Many mushrooms have a tendency to accumulate dangerously high levels of metals or other soil contaminants, and therefore specimens that are growing too close to roads, parking lots, drainage ditches or areas which may be or have been recently sprayed with pesticides would all be good areas to avoid.

A collection of yellow stainer (A. xanthodermus) mushrooms. Usually, but not always, this species has a darker cap color that occasionally cracks quite deeply. This mushroom also lacks the distinct anise-seed or almond smell of other edible Agaricus and is said to smell akin to paint or industrial cleaning chemicals.
A collection of yellow stainer (A. xanthodermus) mushrooms. Note the color of the cut stem and and the cap rim. Occasionally, but not always, this species has a darker cap color that may crack or fissure quite deeply. This mushroom also lacks the distinct anise-seed or almond smell of other edible Agaricus and is said to smell akin to paint thinner or other industrial cleaning chemicals.

Agaricus mushrooms all seem to taste the same to me, although I’m sure that there are differences I’m missing that those with a bit more of a refined palate can appreciate. Apparently ‘the prince’ (A. augustus) is one of the more delicious members of this group of mushrooms and is even disputed by some to be one of the best edible wild mushrooms around. I for one do not believe I have ever come across this species but look forward to the day when if I do happen upon it I have the experience required to confidently collect some to enjoy. Until then, I am quite content with the 2 or more common species that I have encountered thus far and find them all to have a very faint almond or anise-seed odor when freshly cut. When stewed or fried they have a meaty, chewy texture with a distinct and agreeable ‘mushroom’ flavor that easily takes on the characters of foods that it is prepared with. They make a particularly tasty and hardy broth when also cooked with oyster mushrooms (Pleurotus ostreatus) and are exceptional stir fried with plenty of oil and chopped garlic and onions.

Another collection of text-book-worthy A. campestris. These mushrooms were found growing under a shady grove of cherry birch (Betula lenta) with many other patches of the same species mixed with populations of yellow-stainer (A. xanthodermus) mushrooms.
Another collection of text-book-worthy A. campestris. These mushrooms were found growing under a shady grove of historic 200-250 year old copper beech trees with patches of yellow-stainer (A. xanthodermus) throughout the same habitat. Occasionally mature specimens will have darker or minutely cracked spots in the center of their caps. The caps are smooth or slightly rubbery and firm to the touch. Sometimes the caps can have very thin or irregular patches of darker colored scales. The stem, often quite thick, is more fibrous than the flesh of the cap but is also edible cooked.

Here are a few features or habits that you ought to look out for in your specimens to help determine whether or not you have identified the mushrooms correctly as belonging to the Agaricus genus. This list is of course by no means complete and I’m likely leaving out a few other good pointers that definitely should be reviewed by consulting other reputable and reliable resources in order to add to your checklist.

Edible Agaricus mushrooms have a dark brown or chocolate colored spore printnot white or any other color. To make a spore print, take a mushrooms who’s cap has unfurled completely (the cap surface should be slightly or almost flattened) and leave it over a sheet of paper overnight.

most Edible Agaricus mushrooms have pink or rose colored gills which darken and mature to a rich chocolate brown, with A. campestris perhaps displaying a very bright pink most of the time and therefore making it easy. Horse mushrooms (A. arvensis) sometimes have very pale or even white gills which turn to a light lilac before darkening. All other features, including scent, coloration, flesh quality, fruiting times and habitat preferences are all consistent with other edible Agaricus.

– Edible Agaricus mushrooms do not have a distinctly ‘bulb’ shaped or bloated stem base that emerge from an ‘egg’-like sac that develops underground and comes up with the mushroom when it is picked.

– Edible Agaricus mushrooms do not stain a vivid ‘highlighter’ yellow color within seconds of being bruised on the cap or cut at the base of the stem. Some edible species, such as the horse mushroom (A. arvensis) do bruise a faint yellow, but this is very different from the extremely bright staining of A. xanthodermus.

– Edible Agaricus mushrooms do not grow out of living or dead trees or stumps. They are only ever found growing directly out of soil (They may appear to grow out of wood chips, mulch or other natural debris if there is a loose or thin layer above rich soil as is pictured below).

A cluster of meadow mushrooms. These were growing in a shady location as well, somewhat unusual for this and the many closely related species. The edible Agaricus mushrooms species are all very closely related and may very well be complexes of many more closely related species rather than single various species themselves.
An undisturbed cluster of A. campestris mushrooms. These were growing in a shady location under planted cherry birch (Betula lenta) trees in Hamilton. In my mind, it seems more worthwhile to acquaint oneself with the poisonous members of the Agaricus genus rather than the individual edible species, as many of these are inconsistently treated as either a few complexes of very closely related species or possibly one extremely polymorphic species. A universal consensus it seems has not been developed as of yet.

I find the habit of foraging for wild mushrooms to be a very rewarding one and, at least for me, puts things into perspective for me in terms of our true and historic relationship with the earth. Learning to successfully identify and collect edible and/or medicinal mushrooms is something that is innately human, as the majority of our ancestors likely participated in this act, although it was probably not for the purpose of leisure and simple enjoyment but out of absolute necessity and as a celebration of connectivity and the earth’s generosity. It’s just another connection that we can have with ourselves, our true selves, a deep connection and sense of self that many of us may have lost or are questioning in our increasingly ecologically-disassociated cultures.

*Just because your best interests are also my best interests, I would like to extend an offer of assisting you with any wild mushroom ID that you have pertaining to the species or complexes discussed in the above article. If I cannot identify it for you, I can at least recommend some valuable resources that will help you to understanding these mushrooms better and developing more confidence in your own ID. You can get in touch with me for questions or to send me an image of the specimen in question by e-mailing