A Discussion of Edible and Poisonous Mushrooms

One of the most memorable culinary experiences I’ve had was a wild mushroom soup prepared and served at the Mountain Top Inn in Vermont. My wife and I stayed there on one of our anniversaries many years ago. I don’t have the recipe or remember the chef’s name, but I do remember that the soup had a rich and unique flavor quite unlike ordinary mushroom soup. Unfortunately, I don’t even know what kinds of mushrooms were used in the soup.

The forests of New England are absolutely full of mushrooms of many, many varieties. Some are edible and some will kill you dead. Others fall somewhere in between those extremes.  It is not uncommon here to read about people dying of mushroom poisoning. Often it’s an entire family as someone picked the wrong kind of mushrooms and prepared a family dinner with them. Reading about these kinds of events as a child left me with a very healthy and persistent respect for wild mushrooms. If you’re not 100 percent sure what it is, don’t ever eat it.

Not ever having enough confidence to be 100% sure of a mushroom’s identity, I’ve never picked or prepared wild mushrooms for eating. As a result, I have a long-running streak of more than years without ever having fallen victim to any sort of mushroom poisoning, a streak I intend to continue.  The best way to be sure is to bring a qualified and experienced expert along with you to show you the ropes.

Don’t Listen to Me about Edible Mushrooms

Furthermore, I would never rely on any advice about what mushrooms will or will not kill me that I find on someone’s personal blog, no matter how authoritative they may sound. I’d strongly advise you to use that same caution, especially with regard to my blog. I am not a mushroom expert, I am not giving you enough detail to distinguish edible mushrooms from poisonous ones. Do not try this at home.

Building Mushroom Identification Skills

Having said all of that, I’ve always wanted to learn to identify edible mushrooms, but have never really sat down and tried to learn the skill. Now, however, I am in the process of trying to identify every species of plant, including fungi, lichens and other plant-like creatures (as well as every animal species) that grows or lives in my 5.25 acre yard in Southern New Hampshire. Much of my yard, over four acres by my estimate) is forested so there is a wide variety of plants, animals and mushrooms present.

Always Assume the Worst

If I am to identify all those things, I’ll certainly need to know how to identify mushrooms. That means learning all the important (and minor) characteristics of mushrooms that are used by experts to distinguish one from the other. I’ll need to know which ones have near look-alikes, which ones are easy to identify, and which ones are nearly impossible to be sure of without detailed microscopic or chemical analysis. Always err on the side of survival: if there is any possible alternative identification which is not a confirmed edible variety, assume the worst and don’t take chances.

If I can do all of those things, then I should be able to confidently identify some edible mushrooms. The first mushroom that I found and chose for identification turned out to be the Cleft-foot Amanita (Amanita brunnescens), a mushroom listed as “possibly poisonous,” but certainly related to and similar in appearance to many very poisonous varieties of mushroom. In identifying this mushrooms, I learned a few more of the key traits that I should look for, including how to take a spore print to help narrow it down.

Mushroom Propagation Experiment

I’ve also heard from talking to experienced wild mushroom gatherers this summer, that wild, edible mushrooms frequently do not recur in the same location from year to year, although they might show up again several years later in a spot where they were previously found.  This seems a bit curious, but I suspect that there are either spores or rhizomes present once the mushroom has grown there, but they simply need specific weather conditions to begin growing. Many mushrooms grow among deciduous leaf litter or pine needles, which gets me thinking.

“Seeding” New Mushrooms from a Paper Spore Print

If I take a spore print of a mushroom on a piece of plain paper which is made of much the same raw materials as leaf litter… Could I simply take that spore print to a suitable area of the forested part of my yard similar to where the original was found and place that spore-covered sheet of paper under a layer of leaf-litter and get more of the same mushrooms to grow the following year? I don’t know, but I certainly intend to try. After all, if you are “seeding” a specific variety of mushroom in a very specific location and what grows matches the ID marks for the target species, you can have a pretty darn good confidence in the species and edibility of the resulting mushroom, if any indeed result at all. Furthermore, you could cultivate larger quantities in this manner to ensure a good supply in future years.

Bear in mind, I’m not talking about introducing non-native varieties, but simply helping mushroom species that already grow wild in my yard to grow in more places in my yard, assuming, of course, that I find any edible varieties here to begin with.

First Fungus - Cleft-foot Amanita (amanita brunnescens)

Cleft-foot Amanita in a mixed deciduous-
coniferous wood with many oak trees.
Photo by Brad Sylvester, copyright 2011
Do not copy.

I've always wanted to learn to identify mushrooms, particularly the edible ones, but have never gotten around to it. Hopefully, the effort of learning how to identify every species of plant (which does include fungi such as mushrooms) that lives in my yard will help get me there. I have about four acres of forest in my yard, which is home to a wide variety of mushrooms and other fungi, so if I can figure out all of the ones that grow here, I should have a good start of familiar species and I should know most of the key traits to look for in order to properly identify most species.

To start with, I photographed a mushroom in various states of growth as there were several of the same species present. I lifted one out of the ground to look at the base. I photographed the stalk and the underside of the cap. I noted the type of ground and vegetation around it. I thought I had all the bases covered. I was wrong.

For many species of mushrooms, it may be necessary to 1) bruise the mushroom stalk to see if the bruise discolors and if so what color it turns. 2) slice the gills and see if they exude a latex and, if they do, what color it is, and if it changes color after exposure to air. 3) take a spore print and see the color of the spores. A microscopic examination of the spores can also provide an identification key, although that would rarely, if ever, be needed.

In this case, however, I got lucky and believe I have a good identification using the National Audubon Society Field Guide to North American Mushrooms. The mushroom specimen pictured here appears to be the cleft-foot amanita (Amanita brunnescens). A species listed as "possibly poisonous," but closely related (and similar in appearance) to some very seriously poisonous Amanita mushrooms. How did I get to that conclusion? Let's go through the steps.

The vertical split is clearly visible in this specimen of
Cleft-foot Amanita.
Photo by Brad Sylvester, copyright 2011.

First, the general shape of the mushroom with the large, bulbous base, the cap shape, the scales on the top of the cap and the ring around the stalk strongly suggest an amanita according to the shape key in the Audubon Guide. In fact, the shape narrows it down to nine varieties of amanita. When I notice that one of these is called the cleft-foot amanita. I recall that I noticed a distinct  vertical split or cleft in the base (or foot) of each mushroom specimen that I examined. It even shows in some of the photos. Bingo. That's my prime candidate.

Then we run down the other field marks or identification keys for this species. Dark brown to whitish at the margin, check. Patches left over from the universal veil on the top of the cap, check. A collapsing pendant ring (looks like a skirt of skin-like tissue) around the mid or upper stalk, check. Large, bulbous base with an abrupt start from the stalk, check. Gills are free (meaning that the gills are not attached to the central stalk), check. The base has a distinct vertical cleft or split, check. Season: July- October, check. Grows on dry ground among deciduous trees, especially oak, check. Flesh is white, check. Bruises to reddish-brown, unknown (although there is some brownish discoloration where the stalk has been subject to normal wear). Spore print is white, unknown.

The gills and collapsed pendant ring of the cleft-foot amanita
Photo by Brad Sylvester, copyright 2011

Furthermore the field guide provides several color plates which match my photos very closely and lists potential look-alike varieties (some of which are fatally poisonous) which I ruled out one by one by going through their identification guides. I feel quite confident in this identification. The spore print would help me pin it down to the genus Amanita, but I'm very confident at the genus level.

The bulbous base of the Cleft-foot Amanita begins abruptly
Photo by Brad Sylvester, copyright 2011

The cleft-foot amanita while listed as "possibly poisonous" belongs to the same Family and genus as the infamous Death cap mushroom, the deadly Destroying Angel mushroom, the hallucination and coma inducing Panther (a very near look-alike, rarely found in the east) and Fly Agaric mushrooms. Therefore, of course, it should not be eaten under any circumstances.

Creeping Fragile Fern (Cystopteris protrusa) - ID Methods and Data Collection

Creeeping Fragile Fern (cystopteris protrusa)
Photo by Brad Sylvester, copyright 2011, all rights reserved

The plant species for today turned out to be the creeping fragile fern (Cystopteris protrusa), but it was a long two-day journey for me to figure it out. By the way, it’s also called Lowland Brittle Fern, Southern Bladder Fern, and Lowland Bladderfern. For me, identifying the species of the plants that grow in my yard is going to be much more difficult than identifying the animals that live in my yard as I do on my other blog: What Lives in my Yard. I could start off with very easy things like some of the big trees, the garden vegetables (whose names I can read from the seed packets), or some of the perennial flowers, but I want to develop some skills here and find reliable reference sources while I’m conducting this extended bio-survey. So today, I’m kicking it off with a fern, and detailing the process I went through to try to figure out what it was. A good field guide would have helped.

To start with, I chose a wild plant growing in my yard, one that I believe to be native to the region. It is an attractive forest edge border plant. I definitely want to keep it growing where it is and may even think about establishing it in additional areas.

Ordinarily, I’m going to include just one or two photos of each species that I record, because my storage space is limited. However, the first entry is going to be picture heavy, because I’m going to show a wide variety of traits that I captured in hopes of having enough information from which to draw a conclusion about this ferns’ true identity.

Gathering Data about Plants in the Field

Ferns along the forest edge
Photo by Brad Sylvester, copyright 2011, all rights reserved

First, where does it grow? As you can see from the picture to the right, it grows along the forest edge, but looking around my yard, I see that it only grows on the shady side. In other words, the woods are to the south of the ferns and the open yard to the north. That means the ferns are never exposed to bright, direct sunlight. As you can see above in a photo taken at about 1:30 pm on July 20, even at midday, the ferns are in shade or, at most, dappled sunlight. These ones happen to be near the edge of a seasonal brook, but I don’t know whether that is coincidental or not.

Next, I look at the individual leaves and the pattern in which they grow from the stem. This photo shows that they alternate off the main stem. One grows on the left side then a little higher on the stalk one grows from the right side.  For many plants, that’s an important clue. We also notice that other than these complex leaves, there are absolutely no side branches.

Leaf detail of creeeping fragile ferm (Cystopteris protrusa)
Photo by Brad Sylvester, copyright 2011, all rights reserved

These are complicated leaves. They almost resemble fractal patterns in their complexity. Eventually, when we narrow it down to some likely candidates, we should be able to match this pattern up for an exact match. We also note that although the overall shape of the frond is like a triangle, widest at the base and narrowing as it goes toward the tip, the lowermost 2-3 pairs of leaves are a bit shorter than those nearer the center of the plant breaking the true triangular shape.

Meanwhile, from my experience in growing up as a curious young boy in the woods of New England, I know that many ferns have distinctive spore structures on the underside of each leaf. Flipping this one over, I see that it does. These little white dots will each release spores that will fall to the forest floor or drift on the wind, or the back of some furry animal, until it reaches a suitable place to grow. True ferns do not have seeds at all, they reproduce with spores. The shape, arrangement, color and size of these will also help us identify this fern.

Sori of the creeping fragile fern (Cystopteris protrusa)
Photo by Brad Sylvester, copyright 2011, all rights reserved

Individual stems lead from the soil, not clustered stems
Photo by Brad Sylvester, copyright 2011, all rights reserved

What else can we see? At the base of each plant, a single stem emerges from the ground. These ferns don’t grow in clusters with many stems coming from a single base. Honestly, though, I don’t know what a fern’s root system looks like. Is there a bulb down there that stores energy through the winter? Are the roots like any normal plant? Let’s have a look. Carefully digging with my fingers so that I can feel the roots as I go and not damage them beyond all recognition, I find a surprise. The stem of the fern forms a perpendicular attachment to a horizontally running root.  Ah-ha! Although the fern is capable of reproducing through the dispersal of spores, it seems that might just be a back-up plan. Carefully following the “runner” or thick horizontal root, I come to another stem and another fern. Although they look like separate plants from above ground, they are, in fact, parts of the same larger plant.

Rhizome of Cystopteris protrusa showing next year's buds
Photo by Brad Sylvester, copyright 2011, all rights reserved

The other end of this runner heads out toward the lawn. Let’s see what happens there. Ah-ha again! We see a number of tiny branches, also in an alternating pattern, each with a little green bud-like formation at its tip. These are new ferns waiting to break through the surface.  If I didn’t mow the edge here would the ferns keep marching out into the lawn? Would they grow even in the sunlight? Probably not in the full sun, but they’d push the edge and might do ok in the spring and fall when the sun is at a lower angle and the shady area is extended further out into the yard. The root system might extend itself this way for a considerable distance under the lawn, just hoping that one of those underground branches will break through the surface in an area where it can thrive.

Communal Ferns

Which brings up another interesting question: is this whole patch of ferns actually just one plant? Does it grow almost as a colony originating from one single interconnected root system? I might, in fact, only have one fern in my yard, although it covers several hundred square feet. If they are all a signal plant, that also tells us something about its vulnerability to environmental toxins. In theory, an application of a powerful systemic herbicide in one part of the yard might be transported through the runner system to kill an entire patch of ferns where only one or two ferns were actually sprayed.

Similarly, a fungus or bacterial infection might also spread through this underground piping network to take out a whole patch of ferns fairly quickly. If we saw that happening, we might use a shovel to sever the underground runners between healthy areas of the fern patch and unhealthy areas. Then physically dig out and remove the bad part of the colony and hope that whatever it was hadn’t yet reached the rest of the root system.

If we were chemically treating a fungus infection we’d want to make sure that we spray the entire patch rather than just the visibly affected area to prevent it from traveling through the runners to an untreated area. Mind you, this is just conjecture on my part, and would need to be tested experimentally for confirmation.

Fern Propagation

By the way, if we wanted to propagate this very attractive fern as a landscape border or a shady ground cover, we’d dig up and cut a section of the root and bury it in the area where we wanted it to grow. I’m not sure whether we’d need an end piece with the tiny ferns ready-formed or whether any section of the root would be viable. Again, that’s an experiment waiting to happen. I expect that the end piece with the buds would work best and produce new ferns faster and more prolifically, but any significantly sized section of the root would also survive and begin forming buds as well. Just guessing, though.

Anyway, sorry to get distracted, but that’s part of the reason why I’m conducting this bio-survey, to discover things I didn’t know about the things that live and grow right in my own backyard. So for identification purposes we know:

1)      It produces spores from the underside of the leaves and we have images of the sori (a cluster of spore-producing structures).

2)      It has a single stem with alternating leaves growing from it.

3)      We have an image of the exact shape of the leaf.

4)      We know that it reproduces through rhizomes or underground roots and we know what those roots look like.

5)      We know what kind of habitat it likes.

6)      We know what part of the country it lives in.

Is that enough to identify it positively? I think so. First, I’m going to assume that I know it’s a true fern. So let’s start climbing the taxonomy tree. Searching the Internet, I find the University of Michigan’s Sustainable Urban Landscaping Information Series (SULIS) Ferns page. I’m not doing urban landscaping, but it stands to reason that sustainable landscaping would use native plants that grow naturally in the region and habitat which is to be landscaped.

From the information provided on the SULIS page, I’m going to rule out three of the four classes of ferns. What I have is not Psilotopsida of which the only surviving species is the whisk fern. It is not Lycopodiopsida which is comprised of spikemosses, clubmosses and quillworts. It is definitely not Equistopsida which as you might guess contains only horsetails.

That leaves Polypodiopsida (Pteropsida for you Latin-philes). These are the true ferns with 9 sub-classes, 25-300 genera (the plural of genus), and over 12,000 species. Sigh. By the way, SULIS has a page with information about fern propagation which confirms some of my rhizome cutting conjecture, and also reminds me that fern leaves are called fronds, and the spore cases on the underside are called sori.

Let’s get back to our taxonomy. Pteropsida is the class of true ferns within the phylum Pterophyta. I spent some time, unsuccessfully looking for an identification guide online. I’ll need to pick up a good fern field guide. Meanwhile, using Wikipedia, as much as it isn’t a primary research source, I find seven sub-classes: Osmundales, Hymenophyllales, Gleicheniales, Schizaeales, Salviniales, Cyatheales, and Polypodiales. Now I can search each of those and look for enough description to either include or exclude the fern I found in my yard from each subclass.

Wikipedia says 80% of today’s ferns fall into Polypodiales, so let’s start there. Searching again, I find the University of Wisconsin’s  Robert W. Freckman Herbarium page on fern identification, which drills down a bit lower than Polypodiales. Out next choice is between Families. I think my fern is a member of the Dryopteridaceae family, but it’s clear that to go any further, I’m going to need a vocabulary lesson to figure out what terms like rupestral, scandent, dictyostelic, glabrous, pinnatifid, acrostichoid, and too many others to list all really mean. The photos on the site are not sufficient for clear cut identification.

So let’s call it day and come back to this one another time.

Fern Identification Day 2

I came back to the problem of identifying this fern a day later with a fresh idea for searching for online identification guides and it bore fruit immediately -- quite unlike ferns themselves… I finally found a fern identification key at the University of Wisconsin – Green Bay.  It’s on the Herbarium page of the Cofrin Center for Biodiversity. As it asks about specific characteristics being present or not, it includes links on the key terms describing what each is and showing photographic examples. Exactly what I need. A virtual Fern Identification for Dummies. Consequently, it also helps me to learn the terms by using the built-in glossary. This will be my primary resource for fern identification.

At Last! Creeping Fragile Fern

By drilling down through their binary identification system I believe the fern I photographed to be of the genus Cystopteris. One species of that genus, Cystopteris protrusa commonly named the creeping fragile fern, seems to be the most likely candidate as it has some keys distinctions from other Cystopteris species.

1) The creeping fragile fern prefers to grown on soil rather than rocks.

2) It is the only species of the Genus in which the rhizome extends out past the last frond and contains buds for the following year’s fronds.

3) Its range includes New England and it is quite common.

It is the second characteristic which, to me nails the identity as Cystopteris protrusa. You’ll remember that I remarked about the rhizome extension and underground buds. This turned out to be a good exercise, a strong learning experience, and it really highlights the need for thoroughness in the field. I literally had to dig a little deeper to find the characteristic that led me to a good identification on this species.  Genuine curiosity is your best tool for exploration.

At present, I am not abotanist. I've had zero training. I am however, very curious, and quite persistent. In a year from now, I'll be pretty darn good at idenitfying plants by site in the field. If you faollow along with me on this blog and put what you lean into practice, you just might be too.

Cystopteris protrusa Propagation Revisited

By the way, based on the fact that we know the buds represent the following year’s ferns, I expect that to propagate the creeping fragile fern, this terminal portion of the rhizome would need to be transplanted. This may, or may not, hold true for other species of the genus.