Destroying Angel – Amanita bisporigera

The key features of the Destroying Angel are the cup-like volva at the base of the stem, the stark whiteness of the stem, cap, and gills, and the partial veil hanging from the top of the stem just below the gills under the cap.

Common Name: Destroying Angel, Fool’s Mushroom, Death Angel, White Death Cap – The virginal whiteness of all parts of the mushroom are aptly described as angelic – beautiful, good, and innocent. The fact that it is anything but is conveyed by the addition of destroying with death-dealing toxicity.

Scientific Name: Amanita bisporigera – The generic name is taken directly from the Greek word amanitai, probably from the Amanus Mountains of southern Turkey where the noted Greek physician Galen may first have been identified the archetype, Amanita. [1] The specific name indicates that there are only two spores on each of its basidia in contrast to the four spores of other basidiomycete fungi. Virtually indistinguishable from Amanita virosa and Amanita verna which both frequently appear as synonyms in mushroom field guides.

Potpourri:  The destroying angel is a toadstool nonpareil. While the origin of the term toadstool is obscure, it cannot be a coincidence that tode stuhl means death chair in German, the language of the Saxons who emigrated to England. Its notoriety is not only because it is one of several mushrooms that contain deadly poisons called amatoxins, but also due to its close resemblance to Agaricus campestris, the edible field mushroom which is the cousin of the cultivated white button mushroom of supermarkets and salad bars. Both are white, similar in size and shape, and grow in the same habitat, primarily grass under or near trees. The destroying angel is the most dangerous of the numerous doppelgänger mushrooms as the deadly twin of a well-known and often consumed edible.  Misidentification absent knowledge of the subtle physical differences between the two can result in discovering the profound physiological differences with sometimes deadly result. The field white mushroom is nourishing. The angelic white mushroom is Shiva.

The cup at the bottom of the stem is the volva, the bottom half of the universal veil.

The key features that distinguish the destroying angel from similar mushrooms are straightforward if you know what to look for. First and foremost is the volva, (Latin for a covering like a husk or shell) which is the cuplike structure at the base of and surrounding the stem or stipe. The volva is frequently hypogeal, i. e. underground and out of sight. This means that it can only be positively identified by digging up the soil around the base of the mushroom. [2] However, it is the standard and preferred practice among mushroom gatherers to use a knife to cut through the stem cleanly at the base. This is done so the mycelium of the fungus from which the fruiting body mushroom grows is not seriously disturbed. The procedure is analogous to gathering apples from an apple tree. The fungal mycelium and the apple tree survive to produce new mushroom spores and fruit seeds for future generations. Using the standard harvesting technique, it is easy to see how the below the cut volva would not be noted.  White mushrooms must be dug out to the roots to avoid the dilemma of the death mushroom.

The only way to be certain that you have a puffball and not a Destroying Angel is to cut it in half.

The volva is the bottom part of what is known as a universal veil, a thin membrane that envelops the mushroom during the subterranean growth phase to protect the gills and the spores they hold from damage. The universal veil is a characteristic of all mushrooms in the Amanita Family. While there are a few other mushrooms that have a universal veil and its volva (such as the genus Volvariella named for this characteristic feature), it is a reliable identification feature for the destroying angel. All spore-bearing mushrooms are produced by the fungal mycelium underground as an ovoid called a primordium. Once they mature and environmental conditions are promising (like after rain) the extension of the stem causes the universal veil to tear around its circumference to expose the cap and gills of the fruiting body for spore dispersal. The volva is the lower part of the “eggshell” that remains attached to the bottom of the stem. Prior to upward extension, the destroying angel looks like a white egg, similar in appearance to a puffball, another type of edible fungus with which the destroying angel can be confused.  Some field guides include a picture of it in the puffball section to emphasize the danger of mistaken identity. [3] The only way to be absolutely sure is to cut the fungus lengthwise to reveal a cap and gills within.

Many mushrooms have what is known as a partial veil which also helps prevent damage to the reproductive gill surface. It is partial in that it only covers the underside of the cap, extending from the edges of the cap to the stem. When the mushroom cap expands fully, the partial veil also tears, in many cases leaving some remnants around the edges and a ring called an annulus attached to the stem just below the cap. In some cases, the partial veil remnant can be seen hanging like a draped clerical mozetta at the top of the stem. However, this annular ring is not well connected, and in many mushrooms with partial veils, there is no remnant. Most Amanita family mushrooms have both universal veils and partial veils with both a volva at the bottom and a ring around the stem as is the case with the destroying angel. The double protection afforded to the gills must have evolved due to the success of the species in propagation. Amanitas are one of the most prolific of all mushroom families. Partial veils and the remnant annulus are also a characteristic of the Agaricus family, which includes the edible field mushroom Agaricus campestris. They do not have universal veils with the tell tale volva.

The second prominent feature of the destroying angel is the stark whiteness of the cap, stem, and gills that has been described as having a “strange luminous aura that draws the eye” that is “easily visible from one hundred feet away with its serene, sinister, angelic radiance.” [4] The cap is smooth and usually described as viscid or tacky when wet.  This is to distinguish it from most of the other species in the Amanita genus that have warty patches on the cap from the dried out and cracking universal veil like the white dot warts on the bright red cap of the iconic fly agaric (Amanita muscaria).  The glowing purity of the whiteness is a reliable feature for initial field identification. Confirmation by looking for a picture or drawing of a white mushroom with a volva and annular stem ring using a field guide is another matter. One provides only Amanita verna or fool’s mushroom, prevalent only in spring (vernus in Latin). The common name implies that it fools the observer with its deception. [5] A second field guide provides both A. verna as the spring destroying angel, and Amanita virosa (virosus is poisonous in Latin) for mushrooms that appear in the fall with only a passing reference to A. bisporigera. [6] DNA sequencing of fungi has had a profound impact on the eighteenth-century Linnaean system basing taxonomy on physical similarity. It has been shown that all destroying angels of North America are A. bisporigera (with one additional species A. ocreata in California) and that A. verna and A. virosa are only found in Eurasia. Destroying angel is a universal common name for all species for the white mushrooms with volva.

The destroying angel is one of the deadliest mushrooms known. According to one account “misused as a cooking ingredient, its alabaster flesh has wiped out whole families.” [7] The toxic chemicals are called amatoxins (from the generic name Amanita), which are protein molecules made up of eight amino acids in a ring called a cyclopeptide with a molecular weight of about 900. The death dealing amatoxin variant is alpha-amanitin, which destroys RNA polymerase, a crucial metabolic enzyme. RNA polymerase transcribes the DNA blueprint, creating  messenger RNA that transport the codon amino acid recipe used  to make proteins on which all life depends. The ultimate result is rapid cell death. The gastrointestinal mucosa cells of the stomach, the hepatocytes of the liver, and the renal tubular cells of the kidneys are the most severely affected cells because they have the highest turnover rate and are rapidly depleted. The liver is most at risk because the hepatocytes that absorb alpha-amanitins are excreted with the bile and then reabsorbed. The initial stages of amatoxin poisoning start about ten hours after ingestion; the gastrointestinal mucosa cells are the first to be affected resulting in forcible eviction (aka vomiting) of the intruding poisons.  There follows a period of several days of calm as the stomach cells recover somewhat before the storm of  hepatic and renal debilitation. The third and final stage can in severe cases lead to the crescendo of convulsions, coma and death. The lethal dose for 50 percent of the population or LD50 is used by toxicologists as a benchmark for relative virulence. The LD50 for alpha-amanitin is 0.1 mg/kg.  A 70 kg adult will have a 50-50 chance of survival with a dose of 7 milligrams, the amount of alpha-amanitin in one small destroying angel. [8]

The North American Mycological Association (NAMA) received a total of 126 reports of amatoxin poisoning over a period of thirty years, about four annually. The fatality rate has historically been on the order of thirty percent attributed to liver and/or kidney failure; this number has improved over the last several decades to about five percent due to a better understanding of amatoxin physiology effects combined with aggressive therapy. The basic tenet of the treatment is to reduce the toxic concentration in the blood serum as rapidly as possible. Gastric lavation is used if the ingestion was recent enough followed by a thorough purging using emetics to induce vomiting and cathartics to induce evacuation of the bowels (essentially the same effect on the gastrointestinal mucosa cells to expel the poison).  Perhaps the most important therapy is the use of activated charcoal, as amatoxins have a high affinity for adsorption on its surface. Although there is no proven antidote, intravenous injections of penicillin have been used with some apparent benefit. A French physician named Bastien developed a three part procedure using intravenous injections of vitamin C and two types of  antibacterial drugs supplemented with penicillin to successfully treat 15 cases. To unequivocally prove its efficacy, he conducted the ultimate experiment by eating 70 grams of Amanita phalloides, the death cap cousin of the destroying angel and using the protocol on himself. [9] The most promising new treatment is silibinin, an extract of the blessed milk thistle (Silybum marianum), which is sold commercially as Legalon by a German pharmaceutical company. Liver transplant was once considered the last resort for amatoxin poisoning, but that may no longer be necessary. [10]

The destroying angel is not the only mushroom that produces amatoxin, nor is amatoxin the only substance produced by fungi that is inimical to humans. The identification of fungal toxins and the characterization of their imputed symptoms are among the most empirical of forensic science. The facts are based almost entirely on the anecdote. The identification of the mushroom that caused the condition under evaluation is usually a matter of conjecture since the victim has eaten the evidence. To add to the confusion, the alleged offending mushroom may have been consumed with a mixture of other wild foods and fungi gathered over a wide area in obscure nooks.  The dearth of fungal knowledge in the medical community contributes to uncertainly. Poison Control Centers (PCC) were established after World War II to deal with the proliferation of chemicals as clearing houses for information about poisons and their antidotes and treatment protocols. [11] Over the ensuing years, mushroom poisonings accounted for only one half of one percent of all PCC reports (1 in 200). Of those reported, only 10 percent included any information about the mushroom. Based on limited data, NAMA established a toxicology committee in 1985 and began to supplement the PCC data with a separate data base using the input from experienced mycologists and mushroom aficionados. The result to date is a more comprehensive accounting with fairly reliable identification of 80 percent of the mushrooms involved in poisoning. [12] This is a good start but has done little to assuage the beliefs of the general public that most if not all mushrooms are toadstools and that eating wild mushrooms is a fool’s errand, sometimes literally.

One example suffices to point out the irrational fear of amanita mushroom poisoning and the broader category of mycophobia. In 1991, the venerable French reference Petit Larousse Encyclopédie was recalled because the deadly amanita article lacked the appropriate symbol for poison. But this was not enough, since almost 200,000 copies had already been sold.  Several hundred students were hired to visit 6,000 stores throughout Europe and Canada to affix stickers with the appropriate symbol for poison on the pages and append a notice on the cover of the book that it was a new edition. [13]  History has impugned the mushroom as the source of the poison that has dispatched any number of notables, among them Claudius, the fourth Roman Emperor. The perpetrator is alleged to have been his fourth wife Agrippina who wanted her son Nero to succeed to the throne. The death is recounted by the philosopher Seneca the Younger in December 54 CE, only two months after the event occurred. According to his account, it happened quite quickly, the onset of illness and death being separated only by about an hour. [14] The mushroom assassination of Claudius is almost certainly apocryphal, as deadly mushrooms are relatively slow to act; those that act rapidly generally cause gastrointestinal distress that is rarely fatal. Hyperbole is not out of the question. One recent account attributes the disappearance of the Lost Colony of Roanoke to the relocation of the starving colonists to the island of Croatoan. Gorging themselves on the mushroom bounty that they found there, they died a horrible death of grotesque contortions. [15]

References:

1. McIlvaine, C. One Thousand American Fungi, Dover Publications, New York, 1973 pp 2-5

2. Roody. W. Mushrooms of West Virginia and the Central Appalachians, The University Press of Kentucky, Lexington, Kentucky, 2003, pp 62-63.

3. Lincoff, G. National Audubon Society Field Guide to North American Mushrooms, Alfred A. Knopf, New York, 1981. pp 551-552.

4. Russel, B. Field Guide to Wild Mushrooms of Pennsylvania and the Mid-Atlantic, The Penn State University Press, University Park, Pennsylvania, 1935, pp 67-69.

5. McKnight, K and McKnight, V.  Peterson Field Guide to Mushrooms of North America, Houghton Mifflin Company, Boston, 1987, pp 238-239, Plate 27.

6. Pacioni, G. (Lincoff, G, US editor) Guide to Mushrooms, Simon and Schuster, New York, 1981, pp 76-77.

7. Money, N. Mr. Bloomfield’s Orchard, Oxford University Press, Oxford. 2002 p 151

8. Hallen, H. et al. “Gene family encoding the major toxins of lethal Amanita mushrooms”. Proceedings of the National Academy of Sciences. 27 November 2007 Volume  104  Number 48  pp 19097–19101

9. Kendrick, B. The Fifth Kingdom, Focus Publishing, Newburyport, Massachusetts, 2000, pp 319-321.

10. Beug, M. in Fungi Magazine Volume 1 Number 2 Spring 2008. Beug is a Professor Emeritus at Evergreen State College and a member of the NAMA toxicology committee.

11. Wyckoff, A. “AAP Had First Hand in Poison Control Center” AAP News Sept. 2013 http://www.aappublications.org/content/34/10/45

12. Beug, M, et al “Thirty-Plus Years of Mushroom Poisoning: Summary of the Approximately 2,000 Reports in the NAMA Case Registry” Mcllvanea Volume 16 number 2 Fall 2006 pp 47-68.

13, Schaechter, E. In the Company of Mushrooms,  Harvard University Press, Cambridge, Massachusetts, 1997, pp 210-211.

14. Marmon, V. and Wiedemann, T. “The Death of Claudius” Journal of the Royal Society of Medicine, Volume 95, May 2002 pp. 260-261.

15. Spenser, S. “The First Case of Mass Mushroom Poisoning in the New World” Fungi Magazine, Volume 11, Number 4, Fall 2018, pp 30-33.