Nov 28, 2011

Identifying the Fungus among Us

[From my"Wild Ideas" syndicated newspaper column, October 23, 2011]

I knew as a kid that toads didn’t actually sit on toadstools (hookah-smoking caterpillars did that), although I did seem to find an awful lot of toadlets sitting under the umbrella tops of some mushrooms. Maybe they were feeding on insects that were eating the mushrooms, or maybe they were seeking shelter from weather or predators. That was a mystery I never solved.

This large mushroom, most likely a Parasol Mushroom,
kicked off a journey in learning to identify fungi.
This underside view shows the gills under
the cap and the partial veil (ring) on the stalk,
two characteristics that help in identification.
Photos by Pam Owen
Although other things about mushrooms also intrigued and, to some extent, repelled me—their funky look and smell, and their habit of growing in dark, damp places—I never got addicted to the taste of edible ones and became a true ‘shroomer. My interest in fungi got kick-started again when some impressive mushrooms started growing in my driveway during the deluge of rain we got late this summer and early in the fall.

Mushrooms are in the fungus kingdom of living things, separate from plants, animals, and bacteria. We usually think of them as having umbrella-shaped tops, but mushrooms come in a large variety of shapes, sizes, and colors. In my rambles during the wet spell, I came upon white, brown, beige, blue, purple, yellow, orange, green, and red mushrooms with various markings. Shelf mushrooms growing in layers out of trees, club mushrooms that look like coral, puffballs from small orbs to footballs, and delicate “fairy rings” of tiny mushrooms with umbrella tops filled the landscape everywhere I went—from hill to hollow.

One of the amazing things about mushrooms is that much of what we see above ground are merely blooms of a much larger fungus underneath. These blooms are spore carriers, much like flowers that carry a plant’s pollen. The largest living thing in the world is actually a common Honey Mushroom (Armillaria ostoyae). Although its blooms are clustered in small groups that are spread out, they all belong to one underground behemoth extending its rhizomorphs (shoestring filaments) over about 2,384 acres of soil in northeast Oregon's Blue Mountains. It weighs more than 200 tons and is estimated to be about 2,400 years old. Now, that’s a ‘shroom!

The flaky top of the mushroom is a characteristic of
the Parasol Mushroom but of other poisonous species.
Many underground fungi are key to healthy forests in that they break down nutrients that can be absorbed by the tree roots they entwine. Humans, some invertebrates, and voles are among the few consumers of mushrooms. The last, in excreting the spores, enable fungi that live below ground to be dispersed to other areas.

Poisonous mushrooms are commonly referred to as toadstools, and some species have been used for centuries as hallucinogens. Even some mushrooms that are considered edible are dangerous if eaten uncooked.

I’ve always considered all mushrooms to be poisonous until proven otherwise by an expert. Even then, I’d want that expert to take a bite first, then wait a few days for any reaction, before I thought about eating it myself. One genus, Amanita, is responsible 95 percent of the fatalities resulting from mushroom poisoning. According to Wikipedia, the Death Cap (A. phalloides) alone accounts for about 50 percent of these. National Public Radio, in its story “On the Trail of the Death Cap Mushroom,” reported that this species, which has recently been determined through DNA testing to be an invader from Europe, is rapidly spreading along the coast of Northern California, although it also occurs in the East from New York to Virginia.
The mystery mushroom emerged as a button,
as many mushrooms do.
Avoiding the entire Amanita genus is not easy, considering it comprises more than 600 species with a wide variety of shapes and colors. A few are edible, and many resemble edible mushrooms in other genera. Most experts recommend avoiding coming into contact with any Amanita. My brother says a mycologist (mushroom scientist) he knows will not eat any wild mushrooms that grow outside of his geographic area because identification can be so difficult.

To identify the species in my driveway, I checked with other master naturalists and some local ‘shroomers, went a-Googling, and perused my few field guides, including Peterson’s. After my guides proved useful but ultimately inadequate, I ended up ordering a really good one I found for local mushrooms, Mushrooms of Virginia and Central Appalachia, by William C. Roody. From all these, I learned about the major identification points for fungi, including shape, size, color, location, and growing habit.

My mushrooms were white, except for beige-colored flakes on the top of the cap. They emerged from the ground as a ball (button) on a stalk, and then spread out their caps into an umbrella shape that reached 9 inches. The underside of the cap had feathery, spore-carrying ribs that fanned out from the stalk, which put them in the order of gill mushrooms (Agaricales). They also had a ring around the stalk, which was what was left of the cap when it expanded. The base of the stalk, the volva (or veil) was straight, so that ruled out Amanita, whose volva widens at the base.

I never got to the ultimate ID technique—examining the size, color, and shape of the spores—because my subjects kept getting run over by vehicles coming up the drive before I got around to it. I’ll check that next year, if the blooms come up again.

Ultimately, I concluded that my impressive fungus was probably a common, edible Parasol Mushroom (Macrolepiota procera), in the parasol genus. Of course, that doesn’t mean I’m ready to eat it.


  1. I like that you got back into your mushroom fascination when you saw the ones growing in your driveway. Your reluctance about their edibility is totally understandable since a huge percentage of mushrooms in the world are poisonous. I’m glad the ones you found were edible, but it’s still a shame that they kept getting run over!

  2. I just took some very similar photos of the same kind of mushrooms growing near MY driveway/gate. I live in the Valley near Waynesboro. :)

  3. Glad you're enjoying them down there. Despite lots of rain, no sign of them up here where I live yet this summer. I should see them by fall, I hope. ;~}