—Certain fungi growing wild or in cultivated soils and having an expanded top on a hooded stem are known as mushrooms. The common form of mushroom (Agaricus campestris L.) grows wild over a large portion of the United States. It is especially abundant in the autumn, growing sometimes during the night after a warm rain, over large areas. When properly cooked it forms a delicious food and condimental substance, highly prized by connoisseurs and others. Belonging to the family of mushrooms, however, are many poisonous varieties which, when eaten inadvertently, often cause serious illness and sometimes death. For this reason mushrooms sold in the open market should be carefully inspected by experts authorized to see that the poisonous varieties are excluded. It not only requires a good botanist, but also one skilled in the practical differentiation of the different varieties by physical appearance rather than by botanical analysis, to properly separate the poisonous from the edible varieties.
—Mushrooms have been, since historical times, extensively used as human food. In a book written five centuries before the Christian era, Athenée, in his “Banquet of Learned Men,” speaks of the poisoning of a mother and her three children by mushrooms. Hippocrates speaks of a girl who had been poisoned by mushrooms and who was cured by the administration of hot honey and by a hot bath. Theophrastes and Nicandre also speak of mushrooms and the poisoning that occurs therefrom. Both Cicero and Horace make reference to mushrooms. Horace advises that Epicureans should confine themselves to the mushrooms that grow upon meadows and refuse to eat all others on account of the danger from poisoning. Ovid also makes frequent allusions to mushrooms and speaks of the influence of warm rains upon their growth. Tacitus refers to the use of mushrooms for food, and Suétonius, in his “History of the Twelve Cæsars,” relates that the Emperor Claudius was poisoned by a dish of mushrooms. It is, therefore, evident that from the earliest times mushrooms were extensively used and the poisonous properties of some of the varieties understood.
—As has already been mentioned, mushrooms grow wild over a large area of the United States. They are also cultivated very extensively, though not so extensively here as in European countries. The best place for growing cultivated mushrooms is one where the light is excluded or diffused and where the temperature remains reasonably constant. Cellars, caves, and the artificial caverns made by quarrying are peculiarly well suited for the growth of different varieties of fungi, such as mushrooms.
The art of growing mushrooms is not easily acquired. The directions given by the best authorities may be rigidly followed and failure ensue. The skill of the grower appears to be born, not made, and those who have acquired the art succeed where theoretical knowledge fails. For cultural purposes, the Agaricus campestris is most universally employed.
—The soil best suited for the growth of mushrooms is one rich in decayed or decaying vegetable matter. Mushrooms are often found growing in localities where a log or stump has decayed or where the inorganic matter from the manure of cattle or horses has been distributed on the soil. Artificial beds for the growth of mushrooms are made up largely of organic manurial substances.
—Mushrooms are grown from spores. The mushroom produces a brown powdery material which consists of almost innumerable simple cells of ovate shape to which the term “spore” has been applied. A spore is not in the strict sense of the word a seed, but simply a cell which by proliferation produces the new fungus. Generally growers do not use these spores directly in seeding mushroom beds. Each complete spore, however, is, under favorable conditions, capable of proliferation or germination, producing a thread-like growth of a spider-web character which penetrates through the soil, prepared and manured, upon which a spore is germinated. This spider-web-like growth, in the common language of mushroom growers, is called the spawn, more properly called the mycelium of the mushroom. When the conditions are favorable, there are formed on the threads of this mycelium small nodules, which are the earlier stages of the complete fungus itself. From the beginning of this growth until the final production of the mushroom two or three days or even a week may elapse. The earlier periods of this growth take place under ordinary circumstances, but the advent of a warm rain or other extremely favorable conditions causes the budding mushroom to grow at an enormously rapid rate. The mushroom may not be said to have a root, stem, and leaf, as is the case with an ordinary green plant, but is practically a single organism, assuming different shapes which are represented by the different varieties and species of growth.
—There is a very large variety of edible mushrooms differing in form, size, and shape from the Agaricus campestris. In the Washington markets there are four principal kinds of mushrooms which are found growing wild in the vicinity of the city. These comprise the common mushroom—Agaricus campestris, the horse + mushroom—Agaricus arvensis, shaggy mushroom—Coprinus comatus, and the puff-ball—Lycoperdon cyathiforme.
—The proper shed or cellars having been selected, the first thing to do is to see that the temperature is favorable to the growth of the fungi. Temperatures above 60 degrees F., or below 50 degrees F., are not favorable to the growth. The best temperatures are from 55 to 58 degrees. The locality where the mushrooms are grown should be kept very damp and the air highly saturated with aqueous vapor. The reason that mushrooms grow best in covered places, such as has been mentioned, is due to the particularly favorable influence which the even temperature mentioned and a practically saturated atmosphere have upon the growth. In localities where the changes of temperature are not very severe, mushrooms grow very well in the open. In the county of Kent, England, I have seen mushrooms growing in the open garden, where, by covering with straw, they flourish during the greater part of the year. In the winter time the temperature may be kept quite even by the covering to make abundant crops, while in the months of August, September, and October they grow in the open in great abundance.
—The seed bed for the growth of mushrooms, as has already been indicated, is made principally of well decayed stable or stall manure. The manure must be well fermented, thoroughly disintegrated, and exposed for a sufficient length of time to be in the proper condition. Mushrooms cannot be obtained until the heat attending the fermentation of manure has entirely disappeared.
Directions for growing mushrooms cannot be given here, but those who are intending to enter the business should consult the best authorities and begin in a small way until they acquire the necessary skill before commercial success can be obtained.
—Perhaps in no country has the cultivation of mushrooms been carried to such a large extent as in France. The principal industries in France are confined to those regions where artificial caves have been made by the quarrying of building stone. The most extensive caverns of this kind exist in the neighborhood of Paris, near Bordeaux, and particularly in the neighborhood of Sceaux. These artificial caverns are often miles in extent and furnish exceptionally favorable opportunities for the growth of mushrooms. The soils or manures on which they are grown must be carried into these caverns, and experience has shown that mushrooms do not continue to grow well in the same locality, and, therefore, the place of growth must be moved from time to time to different parts of the caves. The galleries of these abandoned quarries are sometimes of enormous extent and are from 30 to 150 feet below the surface. They are generally from seven to ten feet high, but occasionally so low that a man cannot stand upright in them. In general they are wide enough for two rows of beds with a foot way 18 inches wide in the center. Where a mushroom bed has been well prepared and properly seeded, it produces about six pounds of mushrooms per square yard. These mushrooms bring, in the market, an average of about 15 cents per pound. It is stated by some authorities that the reason the bed ceases to bear after a time and has to be abandoned or moved is not because of the exhaustion of the food but is due to the ravages of an insect or fly which produces a worm which is fatal to the growth of the fungus. At any rate, it is customary to abandon the beds after they have been bearing for six or eight months and to return to them after a year, when they are found to again be productive.
It is not expected that the general consumer will become an expert in the selection of mushrooms. Where mushrooms are exposed in a public market, it is the duty of the municipal officers in charge of food products to see to it that poisonous varieties are not exposed for sale. It will be of value, however, to the reader to have some idea of the general shape of some of the more common edible and poisonous varieties. It is generally supposed that mushrooms, toadstools, and puff-balls are entirely distinct species and that only the mushroom, so-called, is edible. On the contrary, there are many edible toadstools and many edible puff-balls, and all three classes of fungi belong to the same general family.
—The nutritive value of mushrooms is not exceptionally high, although there is a popular opinion to the contrary. Frequently it has been stated that the mushroom in the vegetable world holds a similar position to beefsteak among meats, being particularly rich in digestible protein. The analytical data which have been collected from numerous sources on the composition of mushrooms do not bear out this popular impression, but, on the contrary, show that the mushroom is a food product consisting very largely of water and of only very small quantities of protein, fat, and carbohydrates.
The composition of some of the common mushrooms is shown in the following table (Farmers’ Bulletin, No. 79, Mushrooms as Food):
| Water. | Total Nitro- gen. |
Albu- minoid Nitro- gen. |
Non- albu- minoid Nitro- gen. |
Protein. | Fat. | Carbo- hydrates. |
Fiber. | Ash. | |
|---|---|---|---|---|---|---|---|---|---|
| Common mushroom, | 91.30 | 0.60 | 0.36 | 0.24 | 3.75 | 0.20 | 3.50 | 0.80 | 0.50 |
| Shaggy Coprinus, | 92.19 | .45 | .15 | .30 | 2.81 | .26 | 1.40 | .57 | .98 |
| Inky Coprinus, | 92.31 | .36 | .. | .. | 2.25 | .24 | .... | .72 | 1.29 |
| Common Morel, | 89.54 | .49 | .37 | .12 | 3.06 | .50 | 1.60 | .91 | 1.08 |
These data may be compared with the composition of the beefsteak:
| Water, | 62.5 | percent |
| Protein, | 19.5 | „ |
| Fat, | 17.0 | „ |
| Ash, | 1.0 | „ |
From the above data it is seen that the mushroom does not contain anything like the amount of protein found in beefsteak. It has one-third more water, one-sixth as much protein, and only one-fortieth as much fat. Beefsteak contains no carbohydrates except less than one percent of glycogen, while the amount of carbohydrates in the mushroom varies from 1.5 to 3.5 percent. It is evident that the mushroom is principally valuable as a condimental substance and not as a food product.
—It has already been stated that only the expert is able to distinguish between the poisonous varieties of mushrooms and those that are edible. Even the skilled botanist, as well as the expert, may sometimes make mistakes in this matter. Hence the only perfectly sure method of protection against the poisonous varieties is the eating of only those which are cultivated and which are known to be free of poisonous properties. On the other hand, the wild variety, by many connoisseurs, is much more highly valued as being more delicate and palatable. It should also be remembered that the cultivation of mushrooms is not very widely extended, and if the supply of the wild variety should be excluded there would be a great diminution of the quantity which is accessible to the consumer. This would be an especial hardship in the United States, where mushrooms grow wild over such wide areas and so abundantly and where the cultivation of them as compared with some other countries is somewhat restricted. There are some general characteristics by means of which a distinction can be made between the edible and the poisonous varieties.
The following rules are given for the rejection of the probably poisonous mushroom by George Francis Atkinson (“Studies of American Fungi—1900”): “In the selection of mushrooms to eat, great caution should be employed by those who are not reasonably familiar with the means of determination of the species, or those who have not an intimate acquaintance with certain forms. Rarely should the beginner be encouraged to eat them upon his own determination. It is best at first to consult someone who knows or to send first specimens away for determination, though in many cases a careful comparison of the plant with the figures and descriptions given in this book will enable a novice to recognize it. In taking up a species for the first time it would be well to experiment cautiously.”
—“There is no test like the ‘silver-spoon test’ which will enable one to tell the poisonous mushroom from the edible ones. Nor is the presence of the so-called ‘death-cup’ a sure sign that the fungus is poisonous, for Amanita cæsarea has this cup. For the beginner, however, there are certain general rules, which, if carefully followed, will enable him to avoid the poisonous ones, while at the same time necessarily excluding many edible ones.
“1st.—Reject all fungi which have begun to decay, or which are infested with larvæ.
“2d.—Reject all fungi when in the button stage, since the characters are not yet shown which enable one to distinguish the genera and species. Buttons in pasture lands which are at the surface of the ground, and not deep-seated in the soil, would very likely not belong to any of the very poisonous kinds.
“3d.—Reject all fungi which have a cup or sac-like envelope at the base of the stem, or which have a scaly or closely fitting layer at the base of the stem and rather loose warts on the pileus, especially if the gills are white. Amanita cæsarea, however, has a sac-like envelope at the base of the stem and yellow gills as well as a yellow cap, and is edible. Amanita rubescens has remnants of a scaly envelope on the base of the stem and loose warts on the cap, and the flesh, where wounded, becomes reddish. It is edible.
“4th.—Reject all fungi with a milky juice unless the juice is reddish. Several species with copious white milk, sweet or mild to the taste, are edible.
“5th.—Reject very brittle fungi with gills nearly all of equal length where the flesh of the cap is thin, especially those with bright caps.
“6th.—Reject all Boleti in which the flesh changes color where bruised or cut, or those in which the tubes have reddish mouths, also those the taste of which is bitter. Strobilomyces strobilaceus (Scop.) Berk. changes color when cut, and is edible.
“7th.—Reject fungi which have a cobwebby veil or ring when young, and those with slimy caps and clay-colored spores.
“In addition, proceed cautiously in all cases, and make it a point to become very familiar with a few species first, and gradually extend the range of species rather than attempt the first season to eat a large number of different kinds. All puff-balls are edible so long as they are white inside, though some are better than others. All coral-like or club fungi are edible.”
—There is a general opinion that the toadstool is poisonous and the mushroom is not. There is, however, no scientific distinction between the two kinds of fungi, popularly known as toadstools and mushrooms. The distinction is purely an arbitrary one. The small toadstools are often as delicious and as harmless as the small mushroom. The small mushroom, on the other hand, may be as deadly and as undesirable as the worst specimen of toadstool. There is danger especially to two classes of people in the discrimination between the poisonous and edible varieties of mushrooms and toadstools. The first class is composed of those who are practically unaware of the existence of poisonous varieties and the second class of persons are those who claim to be able to tell an edible mushroom from a certain number of tests or claims which they regard as infallible. Both of these classes of persons are apt to be deceived or injured by dangerous varieties.
The following popular signs of distinguishing between the poisonous and non-poisonous varieties are pronounced worthless by Gibson (“Our Edible Toadstools and Mushrooms and How to Distinguish Them”):
1. Pleasant taste and odor.
2. Peeling of the skin of the cap from rim to center.
3. Pink gills, turning brown in older specimens.
4. The stem easily pulled out of the cap and inserted in it like a parasol handle.
5. Solid stems.
6. Must be gathered in the morning.
7. ‘Any fungus having a pleasant taste and odor, being found similarly agreeable after being plainly broiled without the least seasoning is perfectly safe.’
8. Boiling with a ‘silver spoon,’ the staining of the silver indicating danger.
9. Change of color in the fraction of the fresh mushroom.
10. Slimy or sticky on the top.
11. Having the stems at their sides.
12. Growing in clusters.
13. Found in dark, damp places.
14. Growing on wood, decayed logs, or stumps.
15. Growing on or near manure.
16. Having bright colors.
17. Containing milky juice.
18. Having the gill plates of even length.
19. Melting into black fluid.
20. Biting the tongue or having a bitter or nauseating taste.
21. Changing color by immersion in salt-water, or upon being dusted with salt.
“These present but a selection of the more prevalent notions. Taken in toto, they would prove entirely safe, as they would practically exclude every species of toadstool or mushroom that grows. But as a rule the village oracle bases his infallibility upon two or three of the above ‘rules,’ and inasmuch as the entire list absolutely omits the only one test by which danger is to be avoided, it is a seven days’ wonder that the grewsome toadstool epitaph is not more frequent.”
The following tests are regarded as favorable by Gibson:
1. Avoid every mushroom having a cup or suggestion of such, at base; the distinctly fatal poisons are thus excluded.
2. Exclude those having an unpleasant odor, a peppery, bitter, or other unpalatable flavor, or tough consistency.
3. Exclude those infested with worms or in advanced age or decay.
4. In testing others which will pass the above probation let the specimen be kept by itself, not in contact with or enclosed in the same basket with other species.
Begin by a mere nibble, the size of a pea, and gentle mastication, being careful to swallow no saliva, and finally expelling all from the mouth. If no noticeable results follow, the next trial, with the interval of a day, with the same quantity may permit of a swallow of a little of the juice, the fragments of the fungus expelled as before. No unpleasantness following for twenty-four hours, the third trial may permit of a similar entire fragment being swallowed, all of these experiments to be made on an empty stomach. If this introduction of the actual substance of the fungus into the stomach is succeeded by no disturbance in twenty-four hours, a larger piece, the size of a hazelnut, may be attempted, and thus the amount gradually increased day by day until the demonstration of edibility, or at least harmlessness, is complete and the species thus admitted into the “safe” list. By following this method with the utmost caution the experimenter can at best suffer but a slight temporary indisposition as the result of his hardihood, in the event of a noxious species having been encountered, and will at least thus have the satisfaction of discovery of an enemy if not a friend.
It may be said that any mushroom, omitting the Amanita, which is pleasant to the taste and otherwise agreeable as to odor and texture when raw, is probably harmless and may safely be thus ventured on with a view of establishing its edibility. A prominent author on our edible mushrooms (McIlvaine) applies this rule to all the Agarics with confidence. “This rule may be established,” he says: “All Agarics—excepting the Amanitæ—mild to the taste when raw, if they commend themselves in other ways, are edible.” This claim is borne out in his experience, with the result that he now numbers over one hundred species among his habitual edible list out of the three hundred which he has actually found by personal test to be edible or harmless. “So numerous are toadstools,” he continues, “and so well does a study of them define their habits and habitats, that the writer never fails upon any day from April to December to find ample supply of healthy, nutritious, delicate toadstools for himself and family.”
“In gathering mushrooms one should be supplied with a sharp knife. The mushrooms should be carefully cut off an inch or so below the cap, or at least sufficiently far above the ground to escape all signs of dirt on the stems. They should then be laid gills upward in their receptacle, and it is well to have a special basket, arranged with one or two removable bottoms or horizontal partitions, which are kept in place by upright props within, thus relieving the lower layers of mushrooms from the weight of those above them. Such a basket is almost indispensable.
“Before preparing mushrooms for the table, the specimens should be carefully scrutinized for a class of fungus specialists which we have not taken into account, and which have probably anticipated us. The mushroom is proverbial for its rapid development, but nature has not allowed it thus to escape the usual penalties of lush vegetation, as witness this swarming, squirming host, minute grubs, which occasionally honey-comb or hollow its entire substance ere it has reached its prime; indeed, in many cases, even before it has fully expanded or even protruded above ground.
“Like the carrion flies, the bees, and wasps, which in early times were believed to be of spontaneous origin—flies being generated from putrefaction, bees from dead bulls, and the martial wasps from defunct “war-horses”—these fungus swarms, which so speedily reduce a fair specimen of a mushroom to a melting loathsome mass, were also supposed to be the natural progeny of the ‘poisonous toadstool.’ But science has solved the riddle of their mysterious omnipresence among the fungi, each particular swarm of grubs being the witness of a former visit of a maternal parent insect, which has sought the budding fungus in its haunts often before it has fully revealed itself to human gaze, and implanted within its substance her hundred or more eggs. To the uneducated eye these larvæ all appear similar, but the specialist in entomology readily distinguishes between them as the young of this or that species of fly, gnat, or beetle.
“As an illustration of the assiduity with which the history of these tiny scavenger insects has been followed by science, I may mention that in the gnat group alone over seven hundred species have been discovered and scientifically described, many of them requiring a powerful magnifier to reveal their identities.
“Specimens of infected or decaying mushrooms preserved within a tightly closed box—and, we would suggest, duly quarantined—will at length reveal the imago forms of the voracious larvæ; generally a swarm of tiny gnats or flies, with an occasional sprinkling of small glossy black beetles, or perhaps a beautiful indigo-blue insect half an inch in length of most nervous habit, and possessed of a long and very active tail. This insect is an example of the curious group of rove-beetles—staphylinus—a family of insect scavengers, many of whose species depend upon the fungi for subsistence.
“Even the large woody growth known as ‘punk’ or ‘touchwood,’ so frequently seen upon decaying trunks, is not spared. A huge specimen in my keeping was literally reduced to dust by a single species of beetle.
“Considering the prevalence of these fungus hosts, it is well in all mushrooms to take the precaution of making a vertical section through stem and cap, excluding such specimens as are conspicuously monopolized, and not being too critical of the rest, for the over-fastidious gourmet will often thus have little to show for his morning walk. I have gathered a hundred specimens of fungi in one stroll, perhaps not a quarter of which, upon careful scrutiny, though fair of exterior would be fit for the table. The fungus hunter par excellence has usually been there before us and left his mark—a mere fine brown streak or tunnel, perhaps winding through the pulp or stem, where his minute fungoid identity is even yet secreted. But we bigger fungus eaters gradually learn to accept him—if not too outrageously promiscuous—as a natural part and parcel of our Hachis aux Champignons, or our simple mushrooms on toast, even as we wink at the similar lively accessories which sophisticate our delectable raisins, prunes, and figs, to say nothing of prime old Rochefort” (pages 33-34).
E. Faupin, the author of the work “Les Champignons Comestibles et Vénéneux,” gives some valuable hints respecting the confusion of edible and poisonous varieties of mushrooms. He also says that the so-called rules which are often formulated to distinguish the good mushrooms from the bad are nearly all misleading. If they are applicable in a few particular cases they surely are not in all, and consequently ought to be judged as of no value. For instance, it has been commonly said that the mushrooms whose flesh changes color when exposed are poisonous. This is true for certain kinds but it is not true for others. There are, indeed, some mushrooms whose flesh undergoes an alteration when it is exposed and which are, nevertheless, of most excellent quality. As an example of this, the variety known as “delicious lactaire” may be cited. On the contrary there are other kinds whose flesh remains white on exposure and which are decidedly poisonous, as for example Amanita citrina Pers. It is also said that a mushroom whose stem is surrounded by a ring is to be considered edible. This indication is altogether deceptive. Some of the most poisonous varieties have well formed rings. It is also misleading to credit the action of the juice of the mushroom in coloring a piece of silver. It is said that those mushrooms whose juice blackens silver are poisonous, while those which do not are harmless. This perhaps is the most dangerous of all the rules to go by, as some of the most poisonous varieties would be admitted on this test. It is also misleading to suppose, as is commonly the case, that mushrooms which are attacked by insects, larvæ, etc., can be eaten without danger. Likewise misleading is the general opinion that mushrooms whose odor is agreeable or which have no appreciable odor are not poisonous. It is high time to eradicate these misleading notions and to let the people know with certainty that aside from the botanical character there does not exist any particular sign nor any particular means of affirming that a given mushroom is edible or poisonous. Science alone, therefore, has the sole power of teaching to distinguish the poisonous from the non-poisonous varieties. For many years attempts have been made to popularize the science which will give to the people the desired information, but in spite of these efforts the number of cases of poisoning does not seem to diminish, and why? The response is evident. It is because the efforts which have been made by mycologists have not yet been appreciated by the mass of people, and because it has not yet been possible to point out to the public at large the poisonous species. The number of species of poisonous mushrooms which are capable of causing death is happily not very great. The Amanitas and the Volvarias are almost exclusively the poisonous species. Let it be understood, therefore, by the people that there do exist mushrooms which are capable of killing. If the people desire to place themselves out of danger let them begin by learning these varieties. Their number is very limited, as there are only five or six species at most. When they are well known it will be very easy to distinguish them and to recognize all others as edible. Following is a list of the most poisonous mushrooms known, and all that are likely at any time to produce death:
—The most poisonous of the common mushrooms is known as Amanita verna Bull. So active is its poison that this variety has become known as the “deadly Amanita.”
—While it is quite impossible for a manual of this kind to give any directions by which a person, not an expert, may make certain distinctions between the edible and poisonous varieties of mushrooms, it is thought advisable to give a fair technical illustration of the two classes. The common mushroom, Agaricus campestris, is shown in the accompanying Fig. 61,—three-fourths its natural size. The second specimen from the left is young and is in a state of development known as a button. The figure at the extreme left is a larger specimen, showing the slightly checked surface that sometimes occurs in this species. In fresh specimens the surface is white, but various shades of light brown, either checked or plain, are often found. The specimen at the right shows the gills on the lower surface of the cap. These gills in a newly expanded mushroom, fresh from the field, are of a beautiful delicate pale pink color, often with a touch of salmon. In the older samples the gills turn to a light brown and finally almost to a black color. This discoloration is chiefly due to the development of almost innumerable spores from which new plants are propagated. If the stem of a common mushroom be broken off and the cap be laid gills downward on a piece of white paper, the spores will drop off and after a few hours will appear as a brown dust. The usual diameter of full-grown specimens of this variety of mushroom is from 11⁄2 to 3 inches, though many smaller and many larger samples are found.
Fig. 61.—Common Mushroom, Agaricus campestris. Edible. (Three-fourths Natural Size.)—(F. V. Coville, Circular No. 13, Division of Botany, Department of Agriculture.)
This variety of mushroom is the principal one which is exposed upon the markets of Washington. They are especially abundant in the autumn after copious rains often succeeding the usual period of drought in that region. October is the banner month for this variety of mushroom. The mycelium from which the autumn mushroom grows is formed in the spring, and after the dry period of summer the little spheroid granules formed upon the mycelium are capable of absorbing the moisture of the warm autumnal rains and rapidly expand to the full-grown mushroom. After all the conditions of growth are fulfilled it usually requires only a single night for a button to push through the surface of the soil and expand its cap. Mushrooms are particularly obnoxious to the ravages of insects, and it is always advisable that they should be gathered and eaten immediately after they are formed. The insect larvæ attack the mature mushroom, travelling up through the stem into the cap, and decomposition rapidly follows.
Fig. 62.—Edible Mushrooms (Agaricus arvensis Schaeff.).—(F. V. Coville.)
It is easy to determine whether a mushroom is wormy or not by breaking off the stem close to the cap and observing if there are little holes through which the larvæ have passed upward into the cap. The common mushroom occurs most frequently on lawns and in pastures, and especially in neglected fields where weeds have been succeeded by a scant covering of grass. Sometimes during the spring and summer, as well as in the autumn, the common mushroom is found upon the market. These mushrooms usually are produced upon the garbage dumping grounds near the city. The garbage and refuse from the city furnish the manurial conditions required for a speedy development of the mushroom from the mycelium.
Fig. 63.—Shaggy Mushroom, Coprinus comatus. Edible. (Three-fourths Natural Size.)—(Coville, Circular 13, Division of Botany.)
—This variety of mushroom is also one which grows in great abundance in the neighborhood of Washington and in other latitudes affording a similar environment. This specimen is in many respects like Agaricus campestris but the surface of the cap is somewhat darker colored. The ring on the stem is also wider and thicker than in campestris. This variety also grows larger than campestris, and the diameter of the cap is commonly from three to six inches. The figure is only about one-half the natural size. The horse mushroom is frequently confounded with the common mushroom, and there is practically no difference in their edible qualities. It grows preferably in gardens rather than fields, and especially in gardens which have been heavily fertilized. It also frequently appears in old beds composed of decayed stable manure which has been used for forcing beds for early vegetables.
—The accompanying Fig. 63 represents a group of three specimens of this variety of mushroom growing from a single base. The largest one is already showing signs of liquefaction and decomposition and a part of the cap has already disappeared. One of the peculiarities of this species is that beginning with the edge of the cap the whole mushroom dissolves sometimes within a day, when it is full grown, into an inky-black fluid. A portion of this inky fluid has run partly down the white stem of the largest mushroom. The cap of this mushroom, except when it begins to liquefy, resembles somewhat the form of a partially closed umbrella. In the early stages of growth the cap, gills, and stem are white, except the apex of the cap, which is generally dark-colored. The surface of the cap is covered with delicate lacerated scales, the characteristic from which the name comatus or shaggy is derived. The juice from the fresh sample is colorless as water. When it first begins to turn it is wine-colored, and until the juice is very deeply discolored the sample is still edible. After the juice has turned completely black it is considered too old to be eaten. This species of mushroom grows best in shady places, in a soil well supplied with humus. The season in which this variety of mushroom is most abundant is late in the autumn or early in the winter, when the nights are cold but the ground is not yet frozen. The liquefaction and decay of this mushroom come on so quickly that it is not usually infested with larvæ which do not have time to develop before the mushroom is reduced to a shapeless mass. The most common organism found is the myriapod, a thousand-legged worm, which often finds its way between the gills and stem. This cavity should always be examined for worms of this kind when the mushroom is being prepared for the table.
—This variety is one which is interesting both on account of its edible properties and by reason of the circular areas in which it often grows. This illustration is about three-fourths of the natural size. The tendency of this variety to grow in the annual form designated is beautifully shown in the accompanying figure, from a photograph taken on the grounds of the Department of Agriculture. The ring in question is seven feet in diameter and the photograph was taken early in November. The stem in this variety has no ring,—the gills are few and widely separated and the cap as it becomes fully expanded has a peculiar knob-like projection in the center. This gives a characteristic appearance to this variety of mushroom. The cap and stem are colored a pinkish-buff, and the gills have a lighter shade of the same color varying in early growth toward a cream tint. The spores are white and can be observed by placing the cap, as already indicated, on a dark-colored paper, preferably black glazed paper. The fairy ring mushroom is one of the commonest species which grows on the lawns in Washington and vicinity. As many as twenty of these fairy rings have been found on the grounds of the Department of Agriculture in one season. In the earlier days, when superstition was more rife than at present, these rings were supposed to mark the places of the dances of the fairies. Another fanciful cause assigned for the production of the rings was that it was due to the effect of lightning striking the ground and burning the grass in a circle, and thus favoring the growth of fungi. Investigations, however, show that the fairy ring is due to a peculiar way in which the mycelium is produced, which begins at a central point, growing uniformly in all directions a few inches each year. After a while the central portion, being older, begins to die, and thus a small circular band is formed which each year increases in size, growing regularly on the outside and dying as regularly on the inside. The fairy rings are not always complete circles,—they are sometimes broken and often are crescent-shaped. This variety of mushroom is quite permanent, does not tend to decay as rapidly as some, and resists better than most varieties the attacks of insects. They, however, are very small as compared with the other common varieties.
Fig. 64.—Fairy Ring Formed by Marasmius oreades, an Edible Mushroom.—(Coville, Circular 13, Division of Botany.)
—A typical mushroom known as the puff-ball is the variety known as Lycoperdon cyathiforme Bosc. The puff-ball is so plain in its form that a description of its appearance is difficult. Usually the outside is colored brown and the covering is more or less irregularly checked, the white color of the interior showing between the darker, elevated areas. When still quite young the flesh is solid, of a milk-white color, and apparently quite dry. After two or three days it becomes soft, has a yellowish tint, develops a watery and later an amber-colored juice as it continues its development through to the later stages. If the mushroom remains ungathered, the interior dries up into a fine brown powder which is projected into the air when pressed by the finger. It is often blown away by the wind. When the fungus reaches this stage of decay it is very commonly known as “the devil’s snuff-box.” Finally the spores and other dust-like bodies are blown away, and there is left only a dry and leathery framework. In the latter stages the puff-ball is not regarded as edible, not because of its being poisonous, but on account of its dry and leathery consistency. In the neighborhood of Washington puff-balls are found commonly in the autumn on lawns and in gardens, and especially on vacant lots where the soil has remained uncultivated and been closely grazed by cattle. The puff-ball also tends to grow in a fairy ring form, and in the circular area in which it grows the grass is likely to be darker in color, showing the existence of a richer soil. It is only while the interior of the puff-ball is still solid and white, with something like the texture of cheese, that it has its highest edible properties.