Forrex

FIS

NRCanCanadian forest service

For Advanced Users of MMPNW

Hints for Matching

  1. CHOOSE THE 1 TO 8 MOST DISTINCTIVE FEATURES, THEN CLICK ON THE SHOW MATCHES BUTTON. You will be given a list of possible species. Note that you do NOT enter all the characters you know about a mushroom: this gives less accurate results, because the less distinctive characters are more ambiguous.

    If there are 10 species or less, read the descriptions for those species to see if there is a good fit. If one of the descriptions fits well, you have found your species. If not, either the species is not included in the program, or one of the characters you entered is not mentioned in the description. (This may be because the character is wrong or because it is assumed or left out of the description.) There are three options. One is to click Change the Match on the MatchMaker menu, and uncheck a character before clicking SHOW MATCHES again. This is most useful when you have entered 2 to 4 characters, and one could be described differently or not mentioned in the description. Another option is to click Change the Match on the MatchMaker menu, and enter all the characters that you know before clicking SHOW MATCHES again. This is useful when there are not obvious distinct characters. A third option is to use the Reduce Match by 10% button, which appears at the bottom of the main Window rather than the Entry Form. This is most useful when there are a large number of characters checked.

    If there are more than 10 species, you may read all the descriptions given, or read the descriptions with the highest percentage match, or you may narrow your choices. There are two options for narrowing choices. The first and the preferred method is to click on Changing the Match on the Matchmaker menu. Add another distinctive feature and press SHOW MATCHES again. The second is to click on Best Characters on the MatchMaker menu. This gives a list of characters ranked according to the percentage of the remaining species for which that feature holds. (This is an indication of how useful the listed characters are in cutting down the number of choices.) Click on a distinctive feature of your mushroom that is shown by a small percentage of the remaining species, and the species that do not fit that feature will be eliminated.
     
  2. If you have a very distinctive character, such as a green stem, try entering only one or a very small number of characters. Entering a lot of characters will dilute the distinguishing effect of the distinctive character. Note however, that specifying a green stem will match species with greenish gray stems or with green streaking. These species are easily eliminated by reading the descriptions if they are not familiar.
     
  3. If a character does not appear as a choice, look at similar characters to see if it is included with them. Use the glossary to determine similar characters. One reason that a character does not appear is because some characters are not given for enough of the species to make them good separators. Wide, narrow, or ventricose gills are an example, and cystidial characteristics are another. These characters can often be used after the match however, when you compare the descriptions of selected species. (Incidentally, the sparsity of information is also the reason that separate categories are not included for frequency, distribution, and season.)
     
  4. Color descriptions may be finely tuned to achieve better matches. The definition of a color and the colors it will match with are found easily by looking them up in the glossary or the help files. Note that the color any brown is used to include other forms of brown such as red-brown, orange brown, and yellow brown. This is to make it easier to enter some information even when one is not sure of the precise shade of brown. Color interpretation is made more complicated by the fact that different authors use colors in different ways. For instance 'tawny' is used by some authors to describe a yellow brown very close to ochre and by others to imply a strong orange tint to the yellow brown. Generally the program tries to be inclusive: if the description uses the word 'tawny', either 'orange brown' or 'yellow brown' will match. On the other hand, the mushroom will only match with its prominent features. In pretesting the program, a few streaks of green on the cap caused a match with 'green'. Users were confused when the species came up when they asked for mushrooms with green caps. As a result, minor features are no longer matched: white mycelium at the base of the stem does not match with 'white', for instance.
     
  5. If you suspect that your specimen is a certain species, and you are surprised that it matches at a low percentage, click on it after matching, then click on Show Species Characters from the Advanced menu. Compare the characters you checked off with the species characters. You will often find that the missing characters are omitted from the written description or easily confused with similar characters. On the other hand, one of the missing characters may tell you why your specimen is not the species you suspected.
     
  6. CAP is generally marked as 'dry' and 'moist' if either occur in the description, and as 'sticky(viscid)' and 'slimy' if either occur in the description. Although there is obviously a distinction, different authors often describe the same caps with either of these characters. The same is true for the stem. FLESH characters do not include the color of the cap if it is found in the flesh only immediately beneath the cap cuticle. GILL characters do include the color imparted by spores, but not generally that of a darker marginate edge (except for a few Mycenas with dramatically colored edges where leaving the colors out might cause confusion). Seceding gills are included as free as well as their character before seceding, although authors will often not specify that gills may secede. Gills described as having a decurrent tooth are included as decurrent, although they may be notched rather than truly decurrent. Gills are generally marked as 'subdistant' or 'distant' if either occur in the description, and as 'close' or 'crowded' if either occur in the description, but the gill description "close to subdistant" would be rendered as 'close' and 'subdistant'. This is to allow somewhat for the variation that often occurs between authors on gill-spacing. STEM characters do not include the characters of basal mycelium for matches except for colors apart from white that are different from stem. Do not check 'finely hairy' for basal mycelium, for instance, if the rest of the stem is bald. The width measurement is assumed to be the measurement at the top of the stem, although most authors do not specify this. 'Bald' does not exclude pruinose or hoary stem or presence of basal tomentum. ODOR is marked as 'bleach' and 'nitrous' if either occurs in the description, and as 'green corn' and 'spermatic' if either occurs in the description, as the odors are close enough to cause confusion. MICROSCOPIC characters of spores are marked as elliptic or oval if either of these characters occur, since different authors often describe the same spores with either of these characters.
     
  7. Some characters are definitely better than others to use. Very distinct and uncommon characters, like blue color, are good characters to use. Some characters are not good to use in the matching process because they are often omitted from the description. Soft flesh is a good example. Others are not good because the differences between categories are such that different observers may use different words. One person's close gills may be crowded for another observer. An account of the better characters to use is given below.

    The best characters to use for CAP are umbonate, bright colors (red, pink, orange, yellow, green/olive, violet/blue), white, any brown, viscid or slimy (either character will match with either), hygrophanous, peeling, warty, zonate, scaly, erect scales, striate, grooved; intermediate are conical, spherical, cylindric, depressed (especially if funnel-shaped), umbilicate, semicircular, spathulate, kidney, fan-shaped, cream, any brown, light brown/buff, yellow brown/ochre, red brown, black, wrinkled, spotted, pitted, cracked, silky, velvety, woolly, hairy, frosted, patches, incurved, exceeding gills, wavy, lobed, scalloped, appendiculate, fringed; poor characters are convex (often left out), bellshaped (often not mentioned), flat, umbilicate (often indicated as depressed disc), wine, orange brown/cinnamon, gray, purple brown/wine brown, olive brown, gray brown, dark brown, (all colors that are hard to interpret), dry (often omitted), moist, greasy (both hard to interpret), bald, streaked (both variously interpreted), pruinose, granular, flecks (difficult to differentiate from each other).

    The best characters to use for FLESH are bright colors, white, and any brown as for cap; intermediate cream, light brown/buff, yellow brown/ochre, red brown, black; poor are wine, orange brown/cinnamon, gray, purple brown/wine brown, olive brown, gray brown, dark brown, (all colors that are hard to interpret), and all the characters (differences are often subjective and differently described).

    The best characters to use for GILLS are the bright colors, white, any brown, free, adnexed, adnate, decurrent, notched, distant, crowded, dissolving black, edge darker, spotted, mottled; intermediate are cream, light brown/buff, yellow brown/ochre, red brown, black, subdistant, close, forking, anastomosing, interveined (the last three often omitted from descriptions), edge paler or fringed, scalloped, serrate, waxy, brittle; poor are wine, orange brown/cinnamon, gray, purple brown/wine brown, olive brown, gray brown, dark brown.

    The best characters to use for STEM are the bright colors, white, any brown, stem shapes if obvious and marked (with the exception of equal and curved), viscid or slimy (either character will match with either), grooved, spotted, pitted, scaly, erect scales, breaks like chalk, and banded; intermediate are curved, white, cream, any brown, light brown/buff, yellow brown/ochre, red brown, black, striate, fibrillose (if distinct), silky, woolly, pruinose, granular; poor are equal (often left out), wine, orange brown/cinnamon, gray, purple brown/wine brown, olive brown, gray brown, dark brown, (all colors that are hard to interpret), dry (often omitted), moist, greasy (both hard to interpret), bald (omitted), velvety, hairy, frosted, flecks, patches, fragile and tough.

    The best characters to use for VEIL are ring present, glutinous, membranous ring, sheathing ring, cogwheel ring, double ring, colored veil, and the volva types; intermediate are web, fibrillose, thick ring, movable ring; poor are no veils, veils present, no annulus, woolly-cottony, and ring zone.

    Distinct characters for ODOR and TASTE are best (almond, bubble gum, maraschino etc.). Funguslike and pleasant are poor characters on the other hand.

    For SPORE DEPOSIT, white, pale lilac, any brown, and pinkish brown are best because they are unmistakable. The spores that are shades of brown (with the exception of pinkish brown) are also marked as brown.

    The best characters for MICROSCOPIC are round, elliptic, oblong, cylindric, oval, spindle, angular, calyptrate, sausage, spore ornamentations, and Melzer's reaction (not for dark spores); intermediate are almond, lemon, germ pore, thick-walled; poor are bean (because many spores marked elliptic will be slightly bean-shaped in side view).

    For HABITAT, the best characters are ground under conifers, ground under hardwoods, burned ground, on unspecified wood, on conifer wood, on hardwood, on burned wood, on cones, in grass, on other monocots, on berry canes, with or on ferns, on wood chips, on other mushrooms, in sandy areas, on dung, and on fabric; intermediate are on needles, on leaves, on bark, on straw, on hay, in or on moss, with other plant material, clustered or in tufts, swamps or bogs, near snowbanks; poor are in waste places, in arid places, in wet places, on cultivated soil, and in greenhouses.

    All characters for MILK are useful.

    The characters for CHEMICAL would rarely be used in matching and are unlikely to present complete lists of species with those reactions. They would be used more to find some species for which the reactions are helpful.

    COLOR CHANGES are generally not useful unless they are obvious and distinct (with some species of Agaricus, Lyophyllum, Psilocybe and Russula for instance).

    In summary, the more unusual and distinct a character is the more useful it is likely to be.

Searching the Descriptions

The uppermost of three text boxes that appears on the entry form may be used to narrow the match to species that contain a certain word (or words) in their descriptions. For instance, entering the word sclerotium will choose the species that have that word in their descriptions. It would obviously not show species that have sclerotia where that was not mentioned, and it would include a species whose description mentions that it "does not have sclerotia". It other words, it does a straight text search. It does not find a part of a word, unless it is the first part, and does not find a word immediately preceded by a left bracket.

The text search can be combined with other characters. For instance, you could search for all mushrooms with yellow gills and rough spores that mentioned "marginate" in their descriptions.

A simple search is done by entering only the word you want searched. If you want to search for a phrase, there is no need to use single quotes unless the phrase contains the either 'and' or 'or'.

A more complex search may be done to find species that include both of two words or either of two words. This is done by typing the first word, then 'and' or 'or', then the second words. Phrases can be used instead of words, but single quotes must then be used. The search cannot include more than two words or phrases.

There is no need to use single quotes unless you are using 'and' or 'or' with phrases.

A single field such as SPORE DEPOSIT may be specified for the search by using includes or =. For instance, typing gills = blue will find those species that mention blue in the section of the description about gills.

Searches are case sensitive, i.e. they differentiate between capital letters and small letters. There are very few upper case letters in the descriptions apart from names, because sentences are not used.

Examples:

red

includes species with "red", "reddish"
does not find "scored" or "(red)" or "-red"

red alder

includes species with the phrase "red alder"

'alder bogs'

includes species with the phrase "alder bogs"

alder and bogs

finds those with "alder" and "bogs" in description

'alder' and 'bogs'

same as above

alder or bogs

finds species with "alder" and species with "bogs"

'alder' or 'bogs'

same as above

under alders and in bogs

searches for "under alders and in bogs"

'under alders' and 'in bogs'

finds species with both "under alders" and "in bogs"

under alders or in bogs

searches for "under alders or in bogs"

'under alders' or 'in bogs'

finds species with both "under alders" and "in bogs"

habitat = alder

finds those with "alder" under HABITAT

HABITAT = alder

same as above

habitat includes alder

same as above

habitat = alder and bogs

finds those with "alder" and "bogs" under HABITAT

habitat = 'under alders' or 'bogs'

finds "under alders" or "in bogs" under HABITAT

Design Features

Written descriptions are a necessary part of a good computer key. The descriptions given in field guides and monographs are not precise or inclusive enough to allow unequivocal identification of a field specimen by computer matching alone. As with the dichotomous keys used in field guides, it is necessary to compare the specimen with several detailed descriptions, which contain the English nuances that are impossible to transfer to box-like categories. Written descriptions are given in this program and effort has been make to make them easily accessible. In general, for difficult species, technical descriptions have been used where available. On the other hand, descriptions derived from field guides are often used for familiar species because they are more readable and are more likely to be needed by beginners. The description files are in text format (without accents or other formatting to reduce file size; in non-binary format so that they are accessible to a text editor)

Matches at less than 100% are important. The features of a field specimen frequently do not match exactly with data from a description. (Different observers of the same mushroom will also describe it quite differently.) In addition, features which may seem distinctive in a field specimen are often not mentioned in a description. Consequently the correct species will often match at less than 100%. Species that match at less than 100% are included automatically if there are no 100% matches, and whenever the percent match is reduced manually by the user.

Using only positive characters allows the program to be much more efficient. For instance, data is entered if the stem is 'rooting' but not if it is 'not rooting'. (In selected cases where the absence of a character may be important, it is included. The optional Negative button may also be used to indicate the absence of any character, but this is rarely required.) To put this in another way, some programs of this type always use three choices for each character: 'present', 'absent', or 'unknown'. This program uses only two (unless the Negative button is used): 'present', and 'absent or unknown'. In practice, the use of three choices adds only marginally to the power of the program and makes it much slower and more difficult to use.

Characters are equally weighted, both to make the program more efficient and to make the matching process transparent.

The choice of characters to include was difficult. The features that led to a character being included are as follows

  1. The character is included in most standard species descriptions. The breadth of the gills, for instance, is often not mentioned, and was consequently not included.
     
  2. The character is reasonably constant in a wide range of species. The stem features "hollow" and "stuffed" were excluded, for instance. While constant in some species they are variable in many.
     
  3. The term is used uniformly by different writers. The stem feature "cartilaginous" was excluded because most authors use it to mean "firm, tough, pliant", but others "fragile, brittle".

Colors were chosen far enough apart that different observers would choose the same character. For instance "purple" falls under "violet/blue". As an aid, the checkbox help defines colors that fall under that category. In the original design of the program, all color features of the mushroom were included, such as minor streaks, mycelium color, or white bloom. In pretesting this proved confusing to users who would not understand why a species was matched. Now the program leaves out some less prominent features. For instance it would match violet/blue for lilac mycelium at the stem base, but not white for white mycelium.

Some matches will still be surprising to the user. For instance, after entering "Violet/Blue" for a dark blue mushroom, one might be surprised to see matched a bluish gray mushroom. However, it is more important not to miss matches entirely than it is to exclude unexpected ones: they can always be eliminated by reading the descriptions or adding characters to the match.

Categories in the written descriptions also involve some choices. Frequency, distribution, and fruiting season are discussed in NOTES or HABITAT but not given a separate category because information is often lacking for the Pacific Northwest. MILK (or latex) is included with FLESH, VOLVA with VEIL, and CHEMICAL REACTIONS with NOTES because these categories apply to relatively few species.

Some of the mushrooms are included with incomplete descriptions. A source may have mentioned a species for the Pacific Northwest, but may have mentioned only one or two features. When no information is available in the description for a particular character, that mushroom will not be matched if you enter the character. For instance if the description does not give gill color, and you enter the gill color of the mushroom you are trying to identify, the incompletely matched mushroom description will not be shown unless the % Match desired is low enough to allow it. The incompletely described species will obviously match less easily: they are often rare anyway.

Simple language was used where possible without sacrificing precision. While most authors use "stipe" and many use "pileus" and "lamellae", the terms "stem" and "cap" and "gills" are unambiguous and user-friendly to amateurs.

Note on Taxonomy

Genus and species names have been taken from recent references where available. In general, Ainsworth and Bisby's Dictionary (1995) has been followed for taxonomy, although I have not used Dermocybe or Cuphophyllus as genera (the Arora and Bessette field guides do not), and I have used a few genera not (yet) recognized by the Dictionary (such as Chromosera, Leucopholiota, and Paraeccilia) if they are used in field guides or standard references. I have also accepted the separation of Rhodocollybia and Gymnopus from Collybia.

Alternate Latin names are given after the Latin name in the description, and include names thought to represent the same species or part of it. If there is a question about the inclusion of the alternate name in the species, or if the alternate name is used to include more than the main species name, a question mark accompanies the alternate name.

English names are generally taken from field guides. A few obvious English names derived from the Latin name are added: they are enclosed in single quotes.

Name Origins are taken from field guides (enclosed in double quotes) or derived from the Latin or Greek (enclosed in single quotes). Latin and Greek derivations are usually from Composition of Scientific Words, by R.W. Brown.