Toxic Fungi of Western North America

by Thomas J. Duffy, MD


Acetaldyhyde—step in the metabolism of alcohol.

Acetylcholine—quaternary amine and neurotransmitter. See amine below.

Adnate—referring to a very blunt attachment of the gills to the stipe or to an attachment that is about an average gill width.

Adnexed—referring to a thin attachment of a gill where the gill edge at that point is narrowed but the attachment is still at right angles to the stipe, not sinuate.

Agonist—a chemical substance capable of combining with a receptor site on the surface of a cell and initiating a reaction within the cell. See receptor site for lock and key concept.

Alkaloid—a broad class of amines found mainly in plants, including fungi.

Amberlite XAD—an ion exchange resin that removes amines from solution and permits their recovery.

Amino acid—building blocks of peptides. See peptides, which includes proteins.

Amide—carbon to nitrogen bond in peptide.

Amine—an organic nitrogen compound capable of forming salts with acids. (see salt).

Amyloid—blue, gray or black in iodine solutions such as Melzer’s solution.

Anaphylactic shock—an extreme allergic reaction using a different pathway than minor allergies such as "hay fever". The immediate shock (loss of life- sustainable blood pressure) occurs within seconds or minutes. The most common deaths from anaphylactic shock are from bee stings and food such as eggs (but not or exceeding rare with fungi).

Angular—4-7 sided cells, usually referring to spores of the Entolomaceae.

Annulus—ring on the stipe; from the partial veil originally from the cap edge to the stipe and covering the gills.

Annular zone—remains of a ring; usually a roughened area which is noted by catching colored, often brownish or blackish spores, drifting onto the stipe.

Antagonist—see inhibitor.

Antibody—shape sensitive protein that recognizes and destroys specific foreign cellular components.

Antigen—substance that triggers an immune system cell to produce antibodies.

Arcuate—forming an arch of gills, lower edge of the middle of the gills are higher than the lower edge of the ends of the gills.

Ataxia—wobbling or unsteady gait due to nervous system dysfunction.

Autoantibodies—see below.

Autoimmune—a state in which higher organisms produce antibodies that are directed against their own tissue antigens.

Bicyclopeptide—See peptide.

Bicyclic—an organic chemical containing two rings.

Broadly attached—said of gill attachment at the stipe where the attachment is slightly decurrent, adnate or adnexed with a wide attachment at the stipe. See adnate, adnexed, decurrent.

Catalyst—substance that can increase the rate of a chemical reaction without being consumed itself.

Chromatography—separation of a mixture by adsorption on insoluble particles by a moving solvent.

Central nervous system ("CNS")—that portion of the brain and spinal cord within the upper skull (cranium).

Confidence level—statistical estimation of population means from random sample means. The 95th confidence level (roughly 2 standard deviations from the population mean) is most commonly employed; such a statistical finding is likely to be correct 5% of the time at that confidence level, all other considerations being equal.

Coprine—derivative of aminocyclopropanol. An acetaldehyde dehydrogenase inhibitor.

Creatinine—a final product primarily from the break-down of skeletal muscle creatine. It's measurement changes little in human dehydration and is an excellent measure of kidney function.

Cyclopeptides—closed loop derivatives of a peptide (protein fragment).

Decarboxylation—loss of carbon dioxide (CO2) by the decomposition of an organic acid.

Decurrent—gills that run down the stipe or where the attachment at the stipe is wider than the average height of the gill. Short decurrent refers to attachments that run down the stipe, but less than the average height of the gills.

Deliquescent—melting to a liquid state; usually referring to the gills and caps of Coprinus and some species of the Bolbitiaceae.

Dextrinoid—tissue or spores staining golden brown to reddish brown in Melzer’s or other iodine solution.

Diolein—breakdown product of a fatty compound.

Dopamine—an amine (3,4-dihydroxy-phenyethylamine), a neurotransmitter found in the brain and also in peripheral nerves. In addition, it is a precursor of noradrenaline and adrenaline.

DNA—Desoxyribonucleic acid; the building blocks in the nucleus of the cell that form the double helical structure transmitting the genetic code. The double strands are made of nucleotides (a backbone of alternating sugar and phosphate molecules with a base attached to each sugar molecule), residing in the nucleus of the cell. The bases for DNA, abbreviated A, C, G and T (adenine, cytosine, guanine & thymine), encode proteins. A sequence of bases on the DNA –called a promotor—signals the enzyme RNA polymerase to begin the RNA sequence called “messenger RNA”, which transfers the information of DNA to the protein-building machinery of the cell. See RNA.

Ectomycorrhizal—referring to a mutually beneficial relationship between mushrooms and the rootlets of green plants, bushes and trees in which the nutrients of life are exchanged through mycelia branching freely around and between the outer rootlet cells thus forming a connecting mesh fine rootlets. The mushroom provides phosphorus and other simple chemicals to the plant, which provides the mushroom with the more complicated carbon compounds produced by photosynthesis.

Endomycorrhizal—referring to a mutually beneficial relationship between mushrooms and the rootlets of green plants in which the nutrients of life are exchanged through mycelia branching freely around and into rootlet cells. Some species of Armillaria associate in this way with orchids.

Edema—swelling of the body, usually of its dependent parts such as the ankles; a manifestation of over-retention of water in the space between the cells.

Elliptic—elongated, circular structure. By one criteria with a ratio of length to width of 1.15-1.60. Elliptoid—more correctly used for 3-dimensional objects such as spores.

Enzymes—protein catalysts that speed up chemical reactions.

Euphoria—a rosy feeling of happiness and energy.

Fasciculations—small irregular muscle contractions due to the spontaneous contraction of small groups of muscle; usually noted as twitching of bundles of muscle fibers.

Ferrous/Ferric—ferrous iron has an oxidation state of two (charge of 2); ferric refers to iron with an oxidation state of three. Ferrous salts such as ferrous chloride are useful in identification of mushrooms, especially in the genus Russula.

Fibrillose—composed of fine thread-like fibers, longitudinally or radially arranged.

Fibrous—composed of tough, string-like tissue.

Fleshy—soft and relatively bulky; not tough or cartilaginous.

Floccose—with soft, fluffy, cotton-like tufts that readily wipe off a cap.

GABA—gamma-aminobutyric acid, a central nervous system inhibitory transmitter. Increases memory in primates by suppressing “noise” or “static” in information processing.

GI distress or toxicity—nausea, vomiting, diarrhea or epigastric pain.

Glutamic acid and glutamate—an amino acid/salt of that amino acid. (See salt.) Excitatory neurotransmitters in the brain.

Gyromitrin—the precursor of hydrazines in the genus Gyromitra, in particular monomethylhydrazine (MMH) which is a vitamin B6 compound inhibitor. However, not all of MMH toxicity can be explained by this mechanism.

Habit—the characteristic appearance of a mushroom, including its general shape and manner of growth.

Habitat—the natural place of growth.

Haptoglobin—a globulin protein in the plasma that binds free hemoglobin in plasma; should red blood cell destruction take place, then the lab test values of haptoglobin go down since the haptoglobin is bound; bound haptoglobin is immeasurable with standard tests.

Heme—an iron-containing break-down product of hemoglobin.

Hemoglobinuria—free hemoglobin in the urine due to the destruction of red blood cells.

Hemolysis—destruction of red blood cells with spillage of hemoglobin into the plasma.

Heterocyclic—referring to a ring of carbon atoms with a least one other element inserted.

High pressure chromatography—rapid chromatography employing an adsorption column under pressure. See chromatography.

Holotype—the collection on which the describing author named the given mushroom species.

Humus—decaying organic material, often the leaves of decidous trees.

Hydrazine—nitrogen compound with an N-N bond. See gyromitrin and monomethylhydrazine (MMH).

Hydroxylated—Adding a water molecule as an –OH building block to a chemical compound; benzene ring compounds oxidized to phenols during detoxification.

Hygrophanous—changing color on drying, usually referring to a cap which changes from a water-soaked appearance to a ±opaque appearance.

Ibotenic acid—an isoxazole alkaloid that inhibits GABA receptors and activates a glutamate cascade. The name derives from the Japanese "Ibo-Tengu" or long nosed goblin. However, Ibo tengu apparently was applied originally to Amanita "solitaria", not to Amanita muscaria or Amanita pantherina. The chemical formula is α-amino-2,3-dihydro-3-oxo-5-isoxazoleacetic acid. Other oxazoles are muscimol and tricholomic acid.

Immunoassay—Analysis using a reaction of antigen with an antibody and tracer.

Immune system—cells that recognize and destroy specific foreign proteins (or those mistaken for such antigens). See antigen, antibody, autoimmune.

Inamyloid—same as non-amyloid (not changing color in iodine solutions such as Melzer’s agent. See amyloid, dextrinoid for blue-black or brown colors.)

Indole—heterocyclic skeleton of the amino acid tryptophan.

Inhibitor (antagonist)—a molecule that blocks the reaction of a neurotransmitter or enzyme.

Interaction of toxins and drugs—more than a simple additive effect, one toxin or drug increases the effect of the other. A drug or toxin, for example, may increase the effect of a mushroom toxin above that expected by simply adding the two effects together.

Isomer—a compound having the same molecular weight and the same chemical
structure except for 3-dimensional differences. When shown on ordinary 2-dimensional paper, a backwards branch (from the main portion of the molecule) is represented by dotting or similar device rather than a continuous line.

Isoxazole ring—an isomer of oxazole.

Lactic acidosis—a difficultly treatable acidosis usually due to an inadequate supply of oxygen to bodily tissues. Often fatal.

Lignin—a complex organic material (a phenolic polymer) that binds cellulose fibers together to form stiff cell walls in trees and woody plants.

Limb—in botany and mycology, a colored zone at the edge of a leaf or mushroom cap or a membranous extension from a plant or mushroom part are examples of what may be called a “limb”.

Malaise—general but non-specific feeling of being sick.

Methemoglobinemia—a form of hemoglobin which carries oxygen poorly. See methylene blue below.

Methylene Blue—a dye which, though a staining agent in microscopy, is also used medically to reduce ferric heme (methemoglobin) to ferrous heme (normal hemoglobin).

Mitochondria—organelle within cells where energy from respiration is stored and released by oxidative phosphorylation reactions.

Mycorrhizal—referring to a mutually beneficial relationship between mushrooms and the rootlets of green plants (including bushes and trees) in which the nutrients of life are exchanged.

Muscarinic—a compound that stimulates the sympathetic beta receptors directly or indirectly. See discussion under Parasympathetic nervous system.

Muscimol—An isoxazole alkaloid (acts as a GABA receptor inhibitor).

Neurotransmitter—a compound that carries information through a small space of extracellular fluid from one neuron to an adjoining neuron and activates the latter.

Nicotine—an alkaloid that acts as an acetylcholine receptor agonist, but primarily in specific tissues, such as skeletal muscle. (other types of muscle are smooth muscle lining arteries and cardiac muscle)

N [normal]—1 mole per liter. A mole is an international unit that expresses the number of molecules that take place in a chemical reaction.

Octopeptides—An eight unit peptide. (see peptide)

Oliguria—decreased urine output.

Oxoheterocyclic quarternary saltOxo (designating the presence of a carbonyl group) heterocyclic (a ring of carbon compounds with at least one other element inserted) quarternary (a set of four ammonium compounds) salt.

Organelle—specialized structure in the gel-like fluid of a cell. Less commonly used to refer to specialized portions of organs.

Parasympathetic nerves and parasympathetic nervous system—One of the two major autonomic peripheral nervous system divisions. This division uses acetylcholine as its neurotransmitter and over-stimulation produces atropine-like effects with dry mouth, slowing of heart rate etc; also see nicotine. Parasympathetic fibers go to the heart, lungs, ordinary sweat glands etc. Brain cells also trigger using acetylcholine as the neurotransmitter. The other autonomic nervous system division is the sympathetic nervous system.

“Patches”—used to describe fragments of universal veil on the cap (as opposed to “scales” which are innate to the substance of the mushroom cap.

Peptides—chains of amino acids linked by phosphate bonds. Proteins are peptides (commonly referring to the larger chains). Peptides linked head to tail are cyclic peptides.

pH—the common form of reporting acidity. It is the reciprocal of the log to the base 10 of the H+ ion concentration in millimoles per liter. A pH below 7 is acidic; a pH of 7 or higher is alkaline.

Phosphorylation—storage and release of energy in phosphate ester bonds.

Plasma—blood with the red cells removed. Serum is plasma allowed to clot; coagulating factors are removed.

Plasmaphoresis—the selective removal of plasma from whole blood by membrane filtration or other methods. Plasma or a substitute then needs to be replaced.

Plasma exchange—removal of plasma after plasmaphoresis and substitution by donated plasma or albumen (the major protein in plasma).

Platelets—small ±flat organelles in the blood that usually initiate clotting.

Phosphorylated and Dephosphorylated—adding or substracting phosphate-- (PO4-)--having to do with the storage of energy.

Prothrombin time—The protein prothrombin is part of the clotting cascade. It is produced by the liver. Liver damage, however, is only one way that clotting occurs in association with a long prothrombin time.

Proximal tubules and distal tubules—in the kidney, the proximal tubules are the ones nearest the round glomerulus or filtering apparatus; the proximal tubules are followed by the thin loop of Henle and then by the distal tubules (which are microscopically near the glomeruli and thus indistinguishable (in the cortical or outer area of the kidney); these distal tubules are followed by the collecting tubules which run down into the hollow portion of the kidney. These are easily seen as they are microscopically close to that inner portion of the kidney (the medullary area). Loop diuretics used to treat amatoxin poisoning by diuresis (increased urine flow). The loop diuretics work on the loop of Henle and on the distal tubules.

Pulmonary edema—water around and in the air sacs of the lung; an emergency.

Pyridoxal—an oxidized derivative of vitamin B12 which is a co-enzyme for many biochemical reactions.

Quinone—an oxidation product of a dihydroxybenzene compound.

Radioimmunoassay—radioimmunoassay systems use the specificity of antibody reactions and the sensitivity of radioactive tracers to quantitatively measure components in very dilute solution (such as most compounds in serum).

Receptors—portions of cell membranes that are so configured that they accept only certain oppositely configured compounds that fit into these areas like a lock and key. When these receptors accept such compounds, a chemical cascade occurs in which a final reaction occurs within the cell.

RNA—Ribonucleic acid; a chain of nucleotides with a backbone of alternating sugar and phosphate molecules with a nitrogen base attached to each ribose sugar molecule. The strands are made of nucleotides (a backbone of alternating sugar and phosphate molecules with a base attached to each sugar). The bases of RNA are abbreviated A, C, G and U (adenine, cytosine, guanine & uracil) and encode proteins in the ribosomes—tiny structures found in all cells. Free ribosomes scattered in the cytoplasm produce proteins used mainly within the cells; those attached to a membrane called the endoplasmic reticulum produce proteins that are secreted by the cells.

Salts—A chemical compound in which the first portion has a positive ion charge and the second a negative ion charge. Sodium chloride (table salt) is an example, but the salts noted in the text are biochemical ones such as the various amine salts.

Scale—an intrinsic, but differentiated, often slightly elevated flap of cap tissue; note the surface of common Agaricus, Lepiota and Macrolepiota species.

Seceding—refers to ±blunt gill attachments where the gills have now have pulled away from the stipe, lending the appearance of their being free; longitudinal lines are left on the stipe.

Sensu—in the sense of (from the Latin).

Sensu lato—Latin for “in a wide sense”.

Sensu stricto—Latin for “in a narrow sense”.

Serotonin—central nervous system neurotransmitter controlling sleep/waking centers, anaphylactic reactions, some sympathetic nervous system and brain stem reactions. Frequently it acts as a modulator of other neurotransmitter for the autonomic nervous system.

Serum—see plasma.

Slides of fatal Amanita phalloides poisoning (EL,1970 California poisoning):

Sorbitol—a complex sugar which in concentrated oral solution acts to pull water out of the space between the body cells (and eventually from the cells) producing a "hyperosmotic" diarrhea, since the solution is far more concentrated than bodily fluids.

Stipe—stalk part of a mushroom.

Stizolobic and stizolobinic acids—these isomers of ibotenic acid probably have little effect in pantherine poisoning, but they are present and activate excitatory amino acid receptors. Tricholomic acid is another isomer.

Sympathetic nervous system—that portion of the autonomic nervous system, which peripherally has alpha and beta receptors using noradrenaline and adrenaline respectively. Alpha receptor effects include constriction of blood vessels and increased force of the heart beats; beta receptor effects peripherally produce muscarine effects such as salivation and rapid heart rate. Dopamine is a precursor of noradrenaline and adrenaline (as well as a CNS neurotransmitter for nervous tissue in the brain). See parasympathetic nervous system.

Taxon—a taxonomic entity; usually refers to a fungus or fungi whose taxonomic status is unclear (especially as to its status as species, subspecies or form).

Taxonomy—the classification of fungi by genetic, structural and chemical changes; an effort made to find their place in the order of plants according to an evolutionary tree or diagram of such findings.

Thin-layer chromatography—an assay performed in an electromagnetic field on thin silica gel plates. Known and unknown compounds are applied in a solvent and allowed to migrate along the surface. The colors and distances are matched for known and unknown compounds. The colors are brought out by sprays of one or more colorizing compounds (usually cinnamaldehyde spray and then exposure to hydrogen chloride gas for amanitins)

Transvenous—through or into a vein.

Tricholomic acid—an oxazole similar to ibotenic acid and muscimol, but its toxicity is unproven. It is dihydro-ibotenic acid (L-erythro-α-amino-3-oxo-5-isoxazolidine acetic acid). See Ibotenic acid.

Trimester—the 3 divisions of pregnancy, each consisting of 3 months. The first trimester is very important as medications and poisonings occurring here are most likely to damage the fetus.

Tryptophan—an indole-containing aminoacid and the precursor to serotonin. (See serotonin).

Tyrosine—an amino acid and the precursor to the neurotransmitter dopamine and noradrenaline.

Type (collection)—There is or was always an original type collection, whose material may be sent to various institutions for taxonomic study. Unfortunately, the original specimens may be lost from the original herbarium as well as from those donated to other herbariums. In such a situation, a new collection from that area or a previously documented area is matched with descriptions and any fragments in place of the original. Errors also occur.

Urea—an end product of protein breakdown.

Umbo—a central knob left on the cap of a mushroom from an earlier ±conical shaped cap.

Vitamin B6—Pyridoxine: one of 3 forms of B6. Vitamin B6 will combat to some degree CNS toxicity due to vitamin B6 inhibition by gyromitrin.

Viscid, subviscid and glutinous caps vary in the amount of surface “slime”. A viscid cap is slippery to the touch; a subviscid cap is only “tacky” (pulls at the lip when touched to the lip, but needs moistening first); a glutinous cap has an obvious veil of slimy material.

Volva—remnants of a universal veil around the early embryo; it arises from the basal portion of the veil and appears at the base of the stipe as a sac, collar, rings and sometimes, looser, (more amorphous) material.

Warts—here used to indicate agglutinated patches of universal veil tissue on mushroom caps (as opposed to “scales” which are innate to the cap).