First published in Mushroom, The Journal of Wild Mushrooming Fall 2006


 Seen from above, the human brain resembles a shelled walnut:  two nearly symmetrical halves, joined by a tough membrane. This symmetry allows for the simultaneous processing of slightly different information.  Several dedicated structures, the optic chiasm, the anterior commissure, and the corpus callosum – the tough membranes of the walnut -- serve to integrate the processes in nearly real time and knit our perception of the world into a coherent whole.

Western anatomical convention refers to these two halves of the brain as the "dominant" and "sub-dominant" hemispheres. The dominant hemisphere refers to the one in which our linear, sequential, logical tasks are processed:  In short this is our verbal hemisphere.  The sub-dominant half of the brain processes images, spatial relationships, holistic impressions and similar processes: It is the "silent" hemisphere.

 In general, about ninety percent of right handed, right eye dominant males process language in the left hemisphere. They are described as being strongly lateralized. Women and southpaws are less so, having language abilities spread between both hemispheres, and consequently being more able to draw from both hemispheres in an integrated fashion.  "Hookers", are an interesting exception: (Lefties who write with their left hand hooked sharply inward, the tip of the pencil pointing in to the body, the hand itself above the line on which they are writing.) Ninety-nine percent of such hookers are said to be predominantly left-brained.

                                                                                                                   It is rather easy to see these two hemispheres at work when we try to "identify", "remember", or "place" a new observation, say an image in a magazine, on TV, at a cocktail party, or in a dream.  Faces and images are stored in the subdominant, right, hemisphere, but here they lie unnamed. The names are filed in the dominant hemisphere, unattached to the images.  In the breech, we struggle to mend the rift, marry and pull the two halves together.

 If this sounds like a problem you might have in trying to identify a mushroom, you have the basic idea that I want to present and we can go on.   What I hope to do next is to describe several approaches to identifying mushrooms and to suggest ways in which the cognitive sciences might help.


 This is the easiest way to "identify" a new mushroom. Flip through the pictures in book and, once you have got something in the book that resembles what you have in your hand… "presto",  mushroom identified!  This is a very "user-friendly" approach and therefore one of the most popular.   In my introductory courses, I always recommend this approach, and the field guide I recommend is Gary Lincoff's Audubon Guide. There are lots of color-corrected photos of mushrooms thoughtfully arranged to show their defining characteristics to the camera. The guide is extremely portable and Gary's careful text descriptions along with corresponding descriptions of "look-alikes" make this the one you should never leave home without. It is however a guide to the recognition and not the identification of mushrooms.  Gary, himself, has said this.

 Indeed, several factors actually get in the way of the identification process as it was described in the beginning of this article.  The most obvious is the use of "common names" with the photographs. These are the names that get associated with the photos by the user, and it can sound like a comedy routine at times when a group of young mushroom hunters get together  to describe their day's haul of "Chicken Fats" wishing instead that they had but one of "Stuntz' Blue Legs".

The cognitive fix for this problem is easy.  Purchase or devise a set of small labels that can be pasted on to the photographs.  I know of several seasoned, respected mycologists whose memory of binomials and "identification" of fungi were markedly improved after doing so.

To my mind the more serious flaw, though one not immediately obvious to the casual collector is the grouping of mushrooms by gross morphological and color characteristics. This was a trade-off in the printing process.  The benefit was to keep mushrooms of the same color palate together on the same plate in order to enhance the fidelity of the reproductions: the cost was the intermingling of mushrooms irrespective of genus with a corresponding blurring of genera groupings in the mind of the user.  This is a design flaw harder to correct than the pasting of labels, and one I will address later in this article.

Although The Audubon Guide was mentioned by name, several other popular field guides have one or other of these design flaws.  In some, George Barron's 1999 Northeastern Guide for example, some effort is made to keep mushrooms of the same genera together but the color separation suffers.

 All in all, I still try to buy every picture book my budget and shelf space allow.  I know several mycologists who bed down with one or another of these books several times a week, falling asleep with visions of sugar-plumbs dancing in their head. To the extent you follow this practice, the pay-off comes when you see a new or odd mushroom in the woods and an image from a text comes floating up magically, effortlessly.

But then comes the other side of the identification process -- what is it? What is its name?  On to systems of binomial identification.


The traditional way to correctly identify a mushroom is to sit down with a set of keys. With them you methodically, sequentially, analytically and logically make observations and go through a decision tree that at the same time allows you to accept one choice and reject another.  In so doing you follow a set of "binomial choices" – couplets they are often called – that describe a path which leads to a single mushroom.  This "either-or" selection process is the powerhouse that drives much of the scientific process, and is the common denominator of most descriptive work in biology, be it in Field Guides or technical monographs of a single genus.

 This is clearly "left brain" stuff as the following from David Jenkins, Amanita of North America illustrates: (p16)


1. Volva membranous and saccate (cup-like around the base)……………………….           2

1. Volva not saccate (warts, patches, or powdery layers on base) ……………………       4

2. Margin of pileus usually distinctly striate:spores nonamyloid…… Sec. Vaginatae

2. Margin of pileus usually not striate; spores amyloid………………………         3

3. Volval remnants on pileus (if present) also membranous………………. Sec. Phalloidae

3. Volval remnants on pileus friable (small clumps & meal-like pieces); often with
     appendiculate, marginal remnants….……………………………………  Sec. Amidella

4.Margin of pileus usually distinctly striate; spores nonamyloid………………      5

4. Margin of pileus usually not striate (or very faintly striate); spores amyloid..     6

5. Annulus absent and stem with no basal bulb (A. ceciliae complex)…….. Sec. Vaginatae

5. Annulus usually present (or remnants seen on cap margin, buttons, etc) and stem with distinct
basal bulb………………………………………………………………….. Sec. Amanita  

 6. Volva circumscissile with marginate to submarginate basal bulb…Sec. Phalloidae

 6. Volva friable (breaking up into warts, patches, pulverulence, or crusts on stem base, an on pileus) …………………………………………………………           7

7. Pileus usually distinctly colored, margin neither appendiculate nor exceeding gill margins; basal bulb usually relatively small………………………… Sec Validae 

7. Pileus usually white to cream, margin frequently appendiculate nor exceeding gill margins; basal bulb usually relatively large…………………… Sec. Lepidella  

 I find this to be an unusually clean dichotomous key, but notice how more obvious his concepts are if the same information is condensed and listed as a flow chart. [ see fig 1] You will also notice how I was able to add information to this key to further enhance the concepts.

Flow charts like these have several cognitive benefits.

1. They enable both left and right hemispheres to get into the act of processing and digesting information in one "eye gulp".  These are sometimes called "mind maps" and allow the user to "see" the connections more easily.

2. Flow Charts utilize part of the "perceptual – cognitive" process that psychologists and physiologists have identified: the retina of the eye, being part of the brain, makes cognitive distinctions even as it scans the environment.  Observations become sharper, concepts cleaner.

3. Viewers often develop a visceral "feel" for the spatial organization of the material. This becomes a non-verbal clue for retrieval of stored information.

4. It is often easy to close your eyes and call up a mental image of the chart; both hemispheres being used to navigate to the stored information.

5. It becomes much easier to size up concepts developed by different mycologists. When you compare Jenkins's Key to Sections of Amanita with the following from Bas [ fig 2] [editor.. again the lines must be added digitally] their respective paths to the same end points become more obvious.  (The relative merits of these different pathways will become clearer in a later section of this article when we look at synoptic keys.)

By now I trust the merits of taxonomic groupings in a reference or Field Guide can be clearly seen as a step up from those arranged for color consistency in picture books.

 When the casual collector cross the bar and begins to acquire a collection of references the diversity of information often becomes confusing, even overwhelming.  Mind Map flow charts can become life savers in such flux, keeping both interest and understandings afloat. In Northeastern Amanita alone, I have dichotomous keys that go on for pages and pages, some emphasizing field characteristics, some microscopic detail.  Some are user friendly, some notoriously difficult. The design problem shared by all however is revealed when you have to backtrack to try another path. Unless you have a tracking devise built into your brain, you can become helplessly lost. With a flow chart you can see where you are much easier.

Some flow charts are extremely elegant. Should you get a chance to obtain Rene Pomerleau's PANORAMIC KEY TO THE GENERA OF GILLED MUSHROOMS jump on it!  The chart is a 20 inch circular mandala, with nearly 100 genera (circa 1982) laid out on the radial spokes, passing through zones of flesh texture, stipe consistency, presence/absence of structures, spore colors, etc. Fine line drawings with diagnostic detail adorn the margins of the wheel. It is printed on a type of tough paper similar to Tyvek house wrap.  I have kept a copy of this chart in my field key notebook for over 20 years, and aside from some smudges and one scotch tape repair it is as good as new.

Two similarly constructed keys can be found in Hall, et. al. Edible and Poisonous Mushrooms Of The World , p 101 and 102.


In some keys the grid is coarse, in some incredibly fine grained and detailed. For my personal use, and in the introductory to intermediate classes that I teach, I have found it useful to keep the grid coarse, the concepts simple, the forest not obscured by the trees. For conceptual organization I also opt for field observations over microscopic and chemical separations of species concepts. 

Many authors offer a compromise by including a concept for a class lying below the Genus, between the Section and Species designations.  It is often referred to as a "complex" of closely interrelated species.  Alexander Smith refers to it as a "stirps" (pl stirpes), a "central species with its satellites. The stirpes are then grouped into subsections, sections, subgenera, depending on the degree of differences"… among the species. (The Boletes of Michigan, p 18).

 This is a useful concept to keep in mind when constructing your own Flow Chart. It can eliminate clutter and allows for a more streamlined spatial organization of the material in the chart, and consequently in your mind.  This is what many mycologists have in mind when they offer an opinion that what you have in hand is "a Russula, 'close to' laurocerasi".

Another strength of keeping the grid set toward the coarse grain is that you will probably be able to keep up with the changing names fairly easily. They can be penciled in on the field sheets you have, next to the "older" names, and the identifying field concepts - that is, the actual description of the mushroom you have in hand - remain unchanged.

I am not too concerned about having the "latest" name on the tip of my tongue. Not only can this become a "holier (or hipper) than thou" game, but the names often go back and forth depending upon the latest PHD thesis published, manuscript discovered, reagent or technique used.  The mushrooms, of course, remain unchanged and if you have one name a simple Google Search can often give the references to the nomenclatural changes.

Along these lines, I note with interest that Orson and Hope Miller's 2006 version of North American Mushrooms utilizes an updated taxonomic scheme along with a liberal mixture of older names. Collybia, for example has all but disappeared as a genus, being reserved for only a small set of fungi growing from sclerotia on rotting mushrooms, the remainder being distributed among  Xerula, MegacollybaRhodocollybia, Gymnopus, and Clitocybula.  At the same time elsewhere in the text, Suillus pictus remains the name preferred over the "newer" S. spraguei, and Pleuteus cervinus is retained without even a mention of atricapillus. Ah, the things that go on of which we are unaware!

 I particularly like Miller's Taxonomic approach  and have made Flow Charts for many of  the keys he offers in his 1972 edition, modifying them for my own personal interest and use.  Here, for example is my modification of his Key to Amanita species.  The careful observer might notice that in this chart I have left included the California species A. calyptroderma to show how Miller treats it in his key.  Living in the Northeast I would probably not include it in my actual working Key.  The careful observer might also notice that I have added mushrooms in which I have a particular interest, A. volvata, peckiana, sinicoflava, for instance. In one working version of this key I penciled in "Russuloides" next to gemmata, intrigued by an obscure reference to Peck's 1871 collection that I ran across and hoped to verify. Other working keys have references to Jenkins' monograph alongside selected species.


 The figures you see reproduced here are ongoing products.  Unless you are exceptionally comfortable and skilled with the computer keyboard and programs, you will probably want to start by taking out a few sheets of paper, a pencil, eraser, and ruler, sketching out a few drafts by hand before you commit them to the digital domain.  Once put into a word processing package, however, they become rather easy to modify. By the time you have actually completed the Flow Chart you should have a pretty clear understanding of the conceptual scope of the material you are working on, and may ironically find that you no longer need the hard copy of the Flow Chart or Key since the material is now firmly fixed in your mind. File it in your Field Guide Notebook anyway for there is sure to come a time when the memory has faded and a quick glance at the charts is needed to recall the information.


To the extent you become familiar with the concepts, - the forest, so to speak - you may develop a desire to get to know the individual species – the trees- better.  Here is where the technical monographs become an important adjunct to the photographs and keys in field guides. Like the Field Guides, they vary in detail, grid and ease of use.  In some (Alexander Smith's for example) the keys may be relatively straightforward but the observations and discriminations necessary to use them are frustratingly difficult.  In others, Jenkins' Amanita monograph comes to mind, both the Keys and descriptions are relatively easy to use. But even the easiest monographs are not field guides, so some method of encapsulating and transferring material into the field is needed.

One method I have used to advantage has been to devise a set of cards, each coded to a specific quality and to list on the card the names of species sharing that quality. This may sound confusing in the abstract, but it is actually quite simple. Here is one way to do Amanita.

Go to the supermarket and obtain a set of 5X8 spiral bound index cards.  Tear out a few to use as draft cards and then transfer the finished product to the ones still in the bound deck. Keep the grid coarse, the number of cards small, and along the top margin of each, label and sketch the common characteristic.

 For my deck I followed the outline of basal volval characteristic laid out by Lloyd in his 1898 Compilation of the Volvae of the United States.  With modification it has remained a constant feature of monographs ever since.  My current deck has nine cards based upon the following bulb types: 1.Club Shaped, 2.Radial Margin/Small Ring Zone, 3.Single Collar, 4.Multiple Rings, 5.Large Bulb/Cleft or Marshmallow, 6.Base W/Adhering Cup, 7.Stout Saclike Volva, 8.Deep Volva, 9.Turnip Shaped or Rooting Bulb. 

 In North America well over one hundred species of Amanita have been described. Most field guides list, key, illustrate and/or describe only a dozen or so. With these cue cards I can comb from among various references I have and list all of the species that seem relevant to my personal field deck.  In my case I am interested in species that fruit in the northeast and also southern species that may be migrating northward (or now fruiting) as a consequence of global warming.

Relying heavily upon Jenkins' monograph  and work by Rod Tulloss, I have over 60 species, including varieties and undescribed species listed on one or another of the cards. 

Alongside each entry I can list a few differentiating characteristics. My card for  "Deep Volva" (basically Sect. Amidella) lists 8 species as follows:

DEEP VOLVA                                                                                                           PILEUS                                                                                                     

                                                                                                                        RADIAL                   SIZE


W/O ANNULUS                                   var alba white

A. vaginata                gray/white cup  var livida brown                                    yes                    2-4"

A. fulva                       tawny red/brown, white cup                                           yes                    2-4"

A. sinicoflava             yellow ochre, gray cup                                                      yes                    2-3"

A. #44 (Tulloss)         deep brown vaginata

A. volvata                    whitish floccose cap, brownish disc                             no* slight          2-4"

A peckiana                  pinkish tints on cap/inside volva, appendic.margn.    no*                     2-4"


A. spreta                     grayish adhering white volva                                              yes                   2-5"

A. virosa complex                                                                                                      no*                   2-6"

A. volvata  (rarely)

                                                                                                                            * smooth margin , amyloid

Species also are cross-referenced. A. virosa complex, for example, is also listed on the "Stout Saclike Volva" card with descriptors and a reference to "Jenkins (10-15 species) p. 140-141".

 These cards are obviously not the end of the identification process, but represent an intermediate step which can assist with the collection process in the field.  The complete identification of questionable species must be completed at home or in the laboratory with a comparison to the complete description in the literature.


 Some genera are incredibly complex, reminding us of the taxonomists' plaint: "too many species, sharing too few characteristics".  Such is the case in Boletus. Two recent additions to the literature however, Ernst Both's Compendium, and Bessette, Roody, and Bessette's   Color Guide , have been valuable additions in helping us sort through this pile of fleshy pored fungi. The magnitude of the problem is hinted at in the inscription of  B,R&B's text attributed to  Elias Magnus Fries (1794 – 1878).: "No genus has given me more trouble than that of the Boleti."

In this 400 page text, there are over 39 pages of keys dedicated to eastern species, alone. The keys are grouped to a coarse grid e.g. Eastern Net Stipes: Pore Surface at First Red, Orange, Maroon, Brown, or Black, followed by an enhanced dichotomous arrangement with rather fine- grained, detailed entries. Line 1a.of this key, for example, reads " Pore surface black at first, becoming gray in age, bruising grayish orange or darker gray when mature; pileus variable, brown, dull reddish brown, dark olive brown, dark gray, brownish gray or blackish; stipe predominantly reticulate; associated with oak and pine in sandy soil – Tylopilus griseocarneus (p 264)." The entry on p 264 expands to 24 lines of similarly detailed print.

 In both cases the descriptions are clear, clean, and understandable.  But the problem for the field mycologist is obvious; the sheer magnitude of linear sequential information is overwhelming. The number of species is intimidating; the task of navigating a single pathway through the thicket is thorny. 


In contrast to dichotomous keys, synoptic keys are multi access. You are not forced to begin the search from one predetermined observation/choice, but can instead enter from any one of several points. (I remember being stopped cold with one Coprinus key that began with the couplet asking if there was or was not a universal veil, a characteristic that is not immediately obvious to the uninitiated!) 

 There are various types of synoptic keys. Readers with a complete set of M,TJ may wish to review the article ‘Synoptic Genera of Gilled Fungi’ by Fred Rhoades in the Fall 1985 issue.  This approach directs the user to jot down and then cross off various numbers as various descriptive choices are made from those given. The number remaining is that of the Genus of the mushroom you have in hand.

Two "hole punch" systems also suggest themselves. One, the "Quick Key" design, similar to the earliest IBM computer data entry cards, has been used by David Archbald and his associates. These Keys are long out of print, are very hard to come by and the available copies are quite expensive.  The databases of several computer programs in the descriptive biological sciences are based upon the data in this series.  You may check them out on line by doing a Google or Bookfinder search. Unless one has access to a supply of precisely punched data entry cards it would be exceedingly difficult to modify this system for personal use.

A second system, one I have called the "Key Hole Card Punch System", utilizes easy to obtain materials and allows the user to develop his or her personalized multi access set of keys. The "Key-Hole" term is a play on words as part of the Taxonomic Key produces holes that resemble those of old fashioned skeleton key locks. Based upon the original McBee Library Card system, and used by many graduate students before the era of cheap, powerful computers, it requires the user to encode information by punching a series of holes near the margins of the cards. The cards are then sorted by inserting a small stylus through the holes of the entire deck allowing positives to be collected and negatives to escape.

Here is how to do it.  Step one: Go down to Staples and get a set or two of 3X5 1/4" graphed index cards. Also get a 1/4" hole punch and a couple of plastic boxes to hold the finished cards. You will be constructing a deck of cards. Each species you wish to include will have its own card.

Step two: Decide which characteristics you wish to code for. IT IS VERY IMPORTANT THAT YOU GIVE SOME THOUGHT TO THIS BEFORE YOU BEGIN. Once you construct a master card and begin to punch cards for each species, it will be difficult or impossible to change your coding system. This will be a very time consuming process and you will only want to do it once.

For my Bolete deck, I coded for five cap colors along the top margin, five pore colors along the left, seven staining characteristics (color and speed) along the bottom, and four stipe characteristics along the right margin, twenty-one characteristics in all. Each hole is 1/4" in diameter and 1/4" apart, following the 1/4" graphed grid.  In the center of my Master card, I cut out an area through which I could print the Binomial name of the mushroom and other information.

 Step three: Code and cut the cards for the species you want to include in your deck. For the sake of consistency, I based all of my Bolete cards on the descriptions used by a single source; Bessette, Roody and Bessette. It is up-to-date, arguably includes the most complete set of descriptions for North American Boletes assembled under a single cover, uses crisp, clean, understandable language, and includes color illustrations for most of the species described.  I went through both their dichotomous keys and descriptions pulling out all that I thought I might encounter on my forays in the Northeast.

The ugly details: Lay the punched master card on top of a blank card. Write the name of the bolete on the card and mark each hole that applies, e.g. "red cap", "instantly"  "blue staining"," red pored", "reticulated stipe" for Boletus frostii.  Remove the master and add any details you think necessary: page reference, context, synonyms, similar species, etc. Arrows can be used to indicate changes in color. Variability is handled by coding for more than one characteristic.

Sometimes it is possible to key two or more species on the same card by ancillary notations. (In my deck, on the card for Boletus longicurvipes, the secondary species viscidocorrugus and rubropunctus are separated by context and stipe characteristics.)  Because redundancy builds in meaning, it is good practice to also have a separate card for these secondary species.   Punch out the marked holes and go on to the next species/card in your series. Continue until all are included.

The stack of cards you end up with are all now punched for positive characteristics, that is, those associated with the mushroom named.  You now must go through the deck again and mark the negative characteristics. This will become tedious and can become confusing if you try to think about these characteristics as you work on the cards. Here is one way I have found to minimize the tendency to make mistakes.

1. With a felt tip pen, using your master card, mark each characteristic that does not apply to the species coded.  (Based upon the twenty-one characteristics I decided to code for, if I have six (positive) characteristics, I will have fifteen (negative) holes to punch and then cut out.)

2. Before punching out these "negative" holes take the felt tip pen and draw a line from the center of the hole to the margin of the card. This line will mark the escape path.  Do this for each card.

3. Punch out each of the felt tip holes. The lines to the margin will differentiate these from positive holes, which are unmarked.  The lines from the negative holes will start to look like "key holes". Do this for the entire deck.

4. With a pair of scissors, cut out the "escapes" for each of the felt tip marked holes; two snips from the rim of the hole to the margin. The keyhole-look will now become obvious, Do this for the entire deck.

5. Since these cards are hand punched there will be slight differences in the location of the holes. Left as is they tend to "catch" the cards unnecessarily. Sort through the deck a few cards at a time and clean up the differences in the escape paths. Soon the edges will become regular and the cards will fall away readily when you sort through them. Mark or clip one corner to assist in keeping the orientation correct and mark the master card with a line on the top edge do that it can be easily found.

 Using the Synoptic Key Hole Card Deck.

 The advantages of using this prepared deck should become obvious the first or second time you use it. To sort, lay your master card over the entire deck. Beginning with the most obvious characteristic insert a polished toothpick or similar instrument through that hole: e.g. "reticulated" stipe:. all those mushrooms with a reticulated stipe come up, and those without fall away. You then go on to the next most obvious characteristic.

I have over 130 Bolete cards divided between two decks, about 50 in one deck (Leccinum, Tylopilus and a few Suillus ) and the balance (Mostly Boletus) in the other.  From my "Boletus" deck, sorting for "reticulation" immediately eliminates over a third of the cards. A second sort for "red pores" eliminates all but five. A third sort for "blue staining" leaves three cards, one of which is eliminated when I sort for "rapid" staining. Of the two remaining cards, one indicates a "brown" cap (B. pseudo-olivaceous) and one (B. frostii) a "red" cap. Four sorts, perfect match.

Not all sorts, of course, will work this elegantly. Some will end up with a small group of cards necessitating a study of the notations or sub-keys on the cards for further differentiation. Sometimes you end up with an obvious error, but in the majority of the cases the task of the initial identification process becomes as easy as pulling weeds. Not quite, but almost mindless. Given the tangle of the forest of species, who would have thought it to be so easy!!

 There is one obvious problem with this homemade deck: it is somewhat fragile.  The sorts work best with a gentle touch and should be kept dry. Stiffer, smoother, or plasticized cards will work better, but these are hard to come by.  Corrections or revisions to the punched holes can be easily accomplished with "scotch" tape and repunching.  A perfect system would have the picture of the mushroom, along with notes printed on water-resistant cards.

 Throughout this article I have tried to emphasize how the task of identifying mushrooms using published material - Field Guides, Keys, Monographs, photographs and descriptions - can be personalized and enhanced by utilizing a cognitive approach:  using both sides of the brain, so to speak.

 I have not tried to deal with the technique of using portable electronic data bases.   Someone else will have to do that.  I have no doubt that future mycologists will go afield with palm pilots, blackberries, and cell phones hooked up to sensitive image based data systems – the picture books of the future.

 Thanks go to Allan Bessette, David Jenkins, and Steve Stephenson for their gracious permission to use material cited from their works.  All mistakes are mine.

Bill Bakaitis 9/4/06