Meadow Mushrooms

September marks the return of Mushroom Mondays! Let’s start the season with some common, easy-to-identify choice edibles: Meadow Mushrooms (Agaricus spp.).

Photo 1: The smooth, white cap of a Meadow Mushroom in the grass on PEI.

There are several edible Agaricus species commonly called Button, Field, Horse, or Meadow Mushrooms. You’re likely familiar with this genus even if you’ve never heard the name: commercially available White Button, Baby Bella, Cremini, and Portobello mushrooms are all Agaricus bisporus.  There are some Agaricus species that can make you sick, but the good news is there are simple ways to tell the edible from the inedible in this group. You don’t need to know the exact species to know whether it’s safe to eat.

As you might guess, Meadow Mushrooms are found in grassy areas including lawns, parks, pastures, and golf courses. Their caps are smooth and white, making them easy to spot where the grass is short (Photo 1).  If the cap is covered in warts or shaggy scales, it’s not a Meadow Mushroom.

Photo 2: The pinkish gills of a Meadow Mushroom are an important feature for identification. There are toxic, white-gilled mushrooms that share the same habitats.

Under the cap are pinkish gills (Photo 2) which turn dark brown as the mushroom ages. If your mushroom has white gills, it’s not a Meadow Mushroom. Young Meadow Mushrooms have a veil covering the gills, protecting these all-important spore-bearing surfaces until the spores are ready to be released (Photo 3). You can see the same thing on store-bought Button Mushrooms. 

Photo 3: Young Meadow Mushrooms have a protective veil covering the gills. Take a look under the veil to be sure the gills are pink rather than white before you eat it.

Common, inedible Agaricus species fit the description so far, but they have useful differences: the base of the stem will turn bright yellow when cut or bruised and they have an unpleasant smell (often described as similar to cleaning chemicals).  These Yellow Stainers grow in the same habitats as Meadow Mushrooms, and eating them can result in cramps, diarrhoea, and nausea. But if your Agaricus mushroom has pink gills, smells ‘mushroomy’, and doesn’t stain yellow at the base, it’s edible (this test only applies to this group of mushrooms – don’t eat just any mushroom that smells good and doesn’t change colour!).

Meadow Mushrooms can be cooked as you would store-bought mushrooms and have a similar, though slightly stronger and richer, flavour.  That said, it’s always a good idea to try new-to-you fungi in moderation, as not all mushrooms agree with all people.

These fungi are saprobes, breaking down and recycling dead organic matter. Most of us don’t give much thought to the importance of this, but saprobes are critical to nutrient cycling.  This not only allows other plants and animals (including us) to live, it also keeps us from being buried under piles of undecomposed dead things.

This is a great time of year to find Meadow Mushrooms, so keep an eye out for them in grassy areas, especially a few days after a rain. They are delicious and useful parts of PEI untamed!