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• PLATE 1.
• Fig. 1.—Amanita muscaria.
• Fig. 2.—A. frostiana.
• Copyright 1900.

STUDIES OF AMERICAN FUNGI

MUSHROOMS

EDIBLE, POISONOUS, ETC.

BY

GEORGE FRANCIS ATKINSON

Professor of Botany in Cornell University, and Botanist of the

Cornell University Agricultural Experiment Station

Recipes for Cooking Mushrooms, by Mrs. Sarah Tyson Rorer

Chemistry and Toxicology of Mushrooms, by J. F. Clark

WITH 230 ILLUSTRATIONS FROM PHOTOGRAPHS BY THE

AUTHOR, AND COLORED PLATES BY F. R. RATHBUN

SECOND EDITION

NEW YORK

HENRY HOLT AND COMPANY

1903

Copyright, 1900, 1901,
BY
GEO. F. ATKINSON.

INTRODUCTION.

Since the issue of my "Studies and Illustrations of Mushrooms," as Bulletins 138 and 168 of the Cornell University Agricultural Experiment Station, there have been so many inquiries for them and for literature dealing with a larger number of species, it seemed desirable to publish in book form a selection from the number of illustrations of these plants which I have accumulated during the past six or seven years. The selection has been made of those species representing the more important genera, and also for the purpose of illustrating, as far as possible, all the genera of agarics found in the United States. This has been accomplished except in a few cases of the more unimportant ones. There have been added, also, illustrative genera and species of all the other orders of the higher fungi, in which are included many of the edible forms.

The photographs have been made with great care after considerable experience in determining the best means for reproducing individual, specific, and generic characters, so important and difficult to preserve in these plants, and so impossible in many cases to accurately portray by former methods of illustration.

One is often asked the question: "How do you tell the mushrooms from the toadstools?" This implies that mushrooms are edible and that toadstools are poisonous, and this belief is very widespread in the public mind. The fact is that many of the toadstools are edible, the common belief that all of them are poisonous being due to unfamiliarity with the plants or their characteristics.

Some apply the term mushroom to a single species, the one in cultivation, and which grows also in fields (Agaricus campestris), and call all others toadstools. It is becoming customary with some students to apply the term mushroom to the entire group of higher fungi to which the mushroom belongs (Basidiomycetes), and toadstool is regarded as a synonymous term, since there is, strictly speaking, no distinction between a mushroom and a toadstool. There are, then, edible and poisonous mushrooms, or edible and poisonous toadstools, as one chooses to employ the word.

A more pertinent question to ask is how to distinguish the edible from the poisonous mushrooms. There is no single test or criterion, like the "silver spoon" test, or the criterion of a scaly cap, or the presence of a "poison cup" or "death cup," which will serve in all cases to distinguish the edible from the poisonous. Two plants may possess identical characters in this respect, i. e., each may have the "death cup," and one is edible while the other is poisonous, as in Amanita cæsarea, edible, and A. phalloides, poisonous. There are additional characters, however, in these two plants which show that the two differ, and we recognize them as two different species.

To know several different kinds of edible mushrooms, which occur in greater or less quantity through the different seasons, would enable those interested in these plants to provide a palatable food at the expense only of the time required to collect them. To know several of the poisonous ones also is important, in order certainly to avoid them.

The purpose of this book is to present the important characters which it is necessary to observe, in an interesting and intelligible way, to present life-size photographic reproductions accompanied with plain and accurate descriptions. By careful observation of the plant, and comparison with the illustrations and text, one will be able to add many species to the list of edible ones, where now perhaps is collected "only the one which is pink underneath." The chapters 17 to 21 should also be carefully read.

The number of people in America who interest themselves in the collection of mushrooms for the table is small compared to those in some European countries. The number, however, is increasing, and if a little more attention were given to the observation of these plants and the discrimination of the more common kinds, many persons could add greatly to the variety of their foods and relishes with comparatively no cost. The quest for these plants in the fields and woods would also afford a most delightful and needed recreation to many, and there is no subject in nature more fascinating to engage one's interest and powers of observation.

There are also many important problems for the student in this group of plants. Many of our species and the names of the plants are still in great confusion, owing to the very careless way in which these plants have usually been preserved, and the meagerness of recorded observations on the characters of the fresh plants, or of the different stages of development. The study has also an important relation to agriculture and forestry, for there are numerous species which cause decay of valuable timber, or by causing "heart rot" entail immense losses through the annual decretion occurring in standing timber.

If this book contributes to the general interest in these plants as objects of nature worthy of observation, if it succeeds in aiding those who are seeking information of the edible kinds, and stimulates some students to undertake the advancement of our knowledge of this group, it will serve the purpose the author had in mind in its preparation.

I wish here to express my sincere thanks to Mrs. Sarah Tyson Rorer for her kindness in writing a chapter on recipes for cooking mushrooms, especially for this book; to Professor I. P. Roberts, Director of the Cornell University Agricultural Experiment Station, for permission to use certain of the illustrations (Figs. 1–7, 12–14, 31–43) from Bulletins 138 and 168, Studies and Illustrations of Mushrooms; to Mr. F. R. Rathbun, for the charts from which the colored plates were made; to Mr. J. F. Clark and Mr. H. Hasselbring, for the Chapters on Chemistry and Toxicology of Mushrooms, and Characters of Mushrooms, to which their names are appended, and also to Dr. Chas. Peck, of Albany, N. Y., and Dr. G. Bresadola, of Austria-Hungary, to whom some of the specimens have been submitted.

Geo. F. Atkinson,

Cornell University.

Ithaca, N. Y., October, 1900.

SECOND EDITION.

In this edition have been added 10 plates of mushrooms of which I did not have photographs when the first edition was printed. It was possible to accomplish this without changing the paging of any of the descriptive part, so that references to all of the plants in either edition will be the same.

There are also added a chapter on the "Uses of Mushrooms," and an extended chapter on the "Cultivation of Mushrooms." This subject I have been giving some attention to for several years, and in view of the call for information since the appearance of the first edition, it seemed well to add this chapter, illustrated by several flashlight photographs.

G. F. A.

September, 1901.

TABLE OF CONTENTS.

CORRECTIONS.

Page 33, 10th line, for κορνὁς read κοπρὁς.

Page 220, lines 6 and 9, for Gyromytra read Gyromitra.

CHAPTER I.

FORM AND CHARACTERS OF THE MUSHROOM.

Value of Form and Characters.—The different kinds of mushrooms vary in form. Some are quite strikingly different from others, so that no one would have difficulty in recognizing the difference in shape. For example, an umbrella-shaped mushroom like the one shown in Fig. [1] or [81] is easily distinguished from a shelving one like that in Fig. [9] or [188]. But in many cases different species vary only slightly in form, so that it becomes a more or less difficult matter to distinguish them.

In those plants (for the mushroom is a plant) where the different kinds are nearly alike in form, there are other characters than mere general form which enable one to tell them apart. These, it is true, require close observation on our part, as well as some experience in judging of the value of such characters; the same habit of observation and discrimination we apply to everyday affairs and to all departments of knowledge. But so few people give their attention to the discrimination of these plants that few know the value of their characters, or can even recognize them.

It is by a study of these especial characters of form peculiar to the mushrooms that one acquires the power of discrimination among the different kinds. For this reason one should become familiar with the parts of the mushroom, as well as those characters and markings peculiar to them which have been found to stamp them specifically.

Parts of the Mushroom.—To serve as a means of comparison, the common pasture mushroom, or cultivated form (Agaricus campestris), is first described. Figure [1] illustrates well the principal parts of the plant; the cap, the radiating plates or gills on the under side, the stem, and the collar or ring around its upper end.

The Cap.—The cap (technically the pileus) is the expanded part of the mushroom. It is quite thick, and fleshy in consistency, more or less rounded or convex on the upper side, and usually white in color. It is from 1–2 cm. thick at the center and 5–10 cm. in diameter. The surface is generally smooth, but sometimes it is torn up more or less into triangular scales. When these scales are prominent they are often of a dark color. This gives quite a different aspect to the plant, and has led to the enumeration of several varieties, or may be species, among forms accredited by some to the one species.

The Gills.—On the under side of the pileus are radiating plates, the gills, or lamellæ (sing. lamella). These in shape resemble somewhat a knife blade. They are very thin and delicate. When young they are pink in color, but in age change to a dark purple brown, or nearly black color, due to the immense number of spores that are borne on their surfaces. The gills do not quite reach the stem, but are rounded at this end and so curve up to the cap. The triangular spaces between the longer ones are occupied by successively shorter gills, so that the combined surface of all the gills is very great.

Figure. 1.—Agaricus campestris. View of under side showing stem, annulus, gills, and margin of pileus. (Natural size.)

The Stem or Stipe.—The stem in this plant, as in many other kinds, is attached to the pileus in the center. The purpose of the stem seems quite surely to be that of lifting the cap and the gills up above the ground, so that the spores can float in the currents of air and be readily scattered. The stem varies in length from 2–10 cm. and is about 1–1-1/2 cm. in diameter. It is cylindrical in form, and even, quite firm and compact, though sometimes there is a central core where the threads are looser. The stem is also white and fleshy, and is usually smooth.

The Ring.—There is usually present in the mature plant of Agaricus campestris a thin collar (annulus) or ring around the upper end of the stem. It is not a movable ring, but is joined to the stem. It is very delicate, easily rubbed off, or may be even washed off during rains.

Parts Present in Other Mushrooms—The Volva.—Some other mushrooms, like the deadly Amanita (Amanita phalloides) and other species of the genus Amanita, have, in addition to the cap, gills, stem, and ring, a more or less well formed cup-like structure attached to the lower end of the stem, and from which the stem appears to spring. (Figs. [55], [72], etc.) This is the volva, sometimes popularly called the "death cup," or "poison cup." This structure is a very important one to observe, though its presence by no means indicates in all cases that the plant is poisonous. It will be described more in detail in treating of the genus Amanita, where the illustrations should also be consulted.

Figure 2.—Agaricus campestris. "Buttons" just appearing through the sod. Some spawn at the left lower corner. Soil removed from the front. (Natural size.)

Presence or Absence of Ring or Volva.—Of the mushrooms which have stems there are four types with respect to the presence or absence of the ring and volva. In the first type both the ring and volva are absent, as in the common fairy ring mushroom, Marasmius oreades; in the genus Lactarius, Russula, Tricholoma, Clitocybe, and others. In the second type the ring is present while the volva is absent, as in the common mushroom, Agaricus campestris, and its close allies; in the genus Lepiota, Armillaria, and others. In the third type the volva is present, but the ring is absent, as in the genus Volvaria, or Amanitopsis. In the fourth type both the ring and volva are present, as in the genus Amanita.

The Stem is Absent in Some Mushrooms.—There are also quite a large number of mushrooms which lack a stem. These usually grow on stumps, logs, or tree trunks, etc., and one side of the cap is attached directly to the wood on which the fungus is growing. The pileus in such cases is lateral and shelving, that is, it stands out more or less like a shelf from the trunk or log, or in other cases is spread out flat on the surface of the wood. The shelving form is well shown in the beautiful Claudopus nidulans, sometimes called Pleurotus nidulans, and in other species of the genus Pleurotus, Crepidotus, etc. These plants will be described later, and no further description of the peculiarities in form of the mushrooms will be now attempted, since these will be best dealt with when discussing species fully under their appropriate genus. But the brief general description of form given above will be found useful merely as an introduction to the more detailed treatment. Chapter XXI should also be studied. For those who wish the use of a glossary, one is appended at the close of the book, dealing only with the more technical terms employed here.

Figure 3.—Agaricus campestris. Soil washed from the "spawn" and "buttons," showing the young "buttons" attached to the strands of mycelium. (1-1/4 natural size.)

CHAPTER II.

DEVELOPMENT OF THE MUSHROOM.

When the stems of the mushrooms are pulled or dug from the ground, white strands are often clinging to the lower end. These strands are often seen by removing some of the earth from the young plant, as shown in Fig. [2]. This is known among gardeners as "spawn." It is through the growth and increase of this spawn that gardeners propagate the cultivated mushroom. Fine specimens of the spawn of the cultivated mushroom can be seen by digging up from a bed a group of very young plants, such a group as is shown in Fig. [3.] Here the white strands are more numerous than can readily be found in the lawns and pastures where the plant grows in the feral state.

Figure 4.—Agaricus campestris. Sections of "buttons" at different stages, showing formation of gills and veil covering them. (Natural size.)

Nature of Mushroom Spawn.—This spawn, it should be clearly understood, is not spawn in the sense in which that word is used in fish culture; though it may be employed so readily in propagation of mushrooms. The spawn is nothing more than the vegetative portion of the plant. It is made up of countless numbers of delicate, tiny, white, jointed threads, the mycelium.

Mycelium of a Mold.—A good example of mycelium which is familiar to nearly every one occurs in the form of a white mold on bread or on vegetables. One of the molds, so common on bread, forms at first a white cottony mass of loosely interwoven threads. Later the mold becomes black in color because of numerous small fruit cases containing dark spores. This last stage is the fruiting stage of the mold. The earlier stage is the growing, or vegetative, stage. The white mycelium threads grow in the bread and absorb food substances for the mold.

Figure 5.—Agaricus campestris. Nearly mature plants, showing veil stretched across gill cavity. (Natural size.)

Mushroom Spawn is in the Form of Strands of Mycelium.—Now in the mushrooms the threads of mycelium are usually interlaced into definite strands or cords, especially when the mycelium is well developed. In some species these strands become very long, and are dark brown in color. Each thread of mycelium grows, or increases in length, at the end. Each one of the threads grows independently, though all are intertwined in the strand. In this way the strand of mycelium increases in length. It even branches as it extends itself through the soil.

The Button Stage of the Mushroom.—The "spawn" stage, or strands of mycelium, is the vegetative or growing stage of the mushroom. These strands grow through the substance on which the fungus feeds. When the fruiting stage, or the mushroom, begins there appear small knobs or enlargements on these strands, and these are the beginnings of the button stage, as it is properly called. These knobs or young buttons are well shown in Fig. [3]. They begin by the threads of mycelium growing in great numbers out from the side of the cords. These enlarge and elongate and make their way toward the surface of the ground. They are at first very minute and grow from the size of a pinhead to that of a pea, and larger. Now they begin to elongate somewhat and the end enlarges as shown in the larger button in the figure. Here the two main parts of the mushroom are outlined, the stem and the cap. At this stage also the other parts of the mushroom begin to be outlined. The gills appear on the under side of this enlargement at the end of the button, next the stem. They form by the growth of fungus threads downward in radiating lines which correspond in position to the position of the gills. At the same time a veil is formed over the gills by threads which grow from the stem upward to the side of the button, and from the side of the button down toward the stem to meet them. This covers the gills up at an early period.

Figure 6.—Agaricus campestris. Under view of two plants just after rupture of the veil, fragments of the latter clinging both to margin of the pileus and to stem. (Natural size.)

From the Button Stage to the Mushroom.—If we split several of the buttons of different sizes down through the middle, we shall be able to see the position of the gills covered by the veil during their formation. These stages are illustrated in Fig. [4].

As the cap grows in size the gills elongate, and the veil becomes broader. But when the plant is nearly grown the veil ceases to grow, and then the expanding cap pulls so strongly on it that it is torn. Figure [5] shows the veil in a stretched condition just before it is ruptured, and in Fig. [6] the veil has just been torn apart. The veil of the common mushroom is very delicate and fragile, as the illustration shows, and when it is ruptured it often breaks irregularly, sometimes portions of it clinging to the margin of the cap and portions clinging to the stem, or all of it may cling to the cap at times; but usually most of it remains clinging for a short while on the stem. Here it forms the annulus or ring.

Figure 7.—Agaricus campestris. Plant in natural position just after rupture of veil, showing tendency to double annulus on the stem. Portions of the veil also dripping from margin of pileus. (Natural size.)

The Color of the Gills.—The color of the gills of the common mushroom varies in different stages of development. When very young the gills are white. But very soon the gills become pink in color, and during the button stage if the veil is broken this pink color is usually present unless the button is very small. The pink color soon changes to dark brown after the veil becomes ruptured, and when the plants are quite old they are nearly black. This dark color of the gills is due to the dark color of the spores, which are formed in such great numbers on the surface of the gills.

Figure 8.—Agaricus campestris. Section of gill showing tr==trama; sh==sub-hymenium; b==basidium, the basidia make up the hymenium; st==sterigma; g==spore. (Magnified.)

Structure of a Gill.—In Fig. [8] is shown a portion of a section across one of the gills, and it is easy to see in what manner the spores are borne. The gill is made up, as the illustration shows, of mycelium threads. The center of the gill is called the trama. The trama in the case of this plant is made up of threads with rather long cells. Toward the outside of the trama the cells branch into short cells, which make a thin layer. This forms the sub-hymenium. The sub-hymenium in turn gives rise to long club-shaped cells which stand parallel to each other at right angles to the surface of the gill. The entire surface of the gill is covered with these club-shaped cells called basidia (sing. basidium). Each of these club-shaped cells bears either two or four spinous processes called sterígmata (sing. sterígma), and these in turn each bear a spore. All these points are well shown in Fig. [8]. The basidia together make up the hymenium.

Figure 9.—Polyporus borealis, showing wound at base of hemlock spruce caused by falling tree. Bracket fruit form of Polyporus borealis growing from wound. (1/15 natural size.)

Wood Destroying Fungi.—Many of the mushrooms, and their kind, grow on wood. A visit to the damp forest during the summer months, or during the autumn, will reveal large numbers of these plants growing on logs, stumps, from buried roots or rotten wood, on standing dead trunks, or even on living trees. In the latter case the mushroom usually grows from some knothole or wound in the tree (Fig. [9]). Many of the forms which appear on the trunks of dead or living trees are plants of tough or woody consistency. They are known as shelving or bracket fungi, or popularly as "fungoids" or "fungos." Both these latter words are very unfortunate and inappropriate. Many of these shelving or bracket fungi are perennial and live from year to year. They may therefore be found during the winter as well as in the summer. The writer has found specimens over eighty years old. The shelves or brackets are the fruit bodies, and consist of the pileus with the fruiting surface below. The fruiting surface is either in the form of gills like Agaricus, or it is honey-combed, or spinous, or entirely smooth.

Figure 10.—Polyporus borealis. Strands of mycelium extending radially in the wood of the same living hemlock spruce shown in Fig. [9]. (Natural size.)

Mycelium of the Wood Destroying Fungi.—While the fruit bodies are on the outside of the trunk, the mycelium, or vegetative part of the fungus, is within the wood or bark. By stripping off the bark from decaying logs where these fungi are growing, the mycelium is often found in great abundance. By tearing open the rotting wood it can be traced all through the decaying parts. In fact, the mycelium is largely if not wholly responsible for the rapid disintegration of the wood. In living trees the mycelium of certain bracket fungi enters through a wound and grows into the heart wood. Now the heart wood is dead and cannot long resist the entrance and destructive action of the mycelium. The mycelium spreads through the heart of the tree, causing it to rot (Fig. [10]). When it has spread over a large feeding area it can then grow out through a wound or old knothole and form the bracket fruit body, in case the knothole or wound has not completely healed over so as to imprison the fungus mycelium.

Plate 2, Figure 11.—Mycelium of Agaricus melleus on large door in passage coal mine, Wilkesbarre, Pa. (1/20 natural size.)

Fungi in Abandoned Coal Mines.—Mushrooms and bracket fungi grow in great profusion on the wood props or doors in abandoned coal mines, cement mines, etc. There is here an abundance of moisture, and the temperature conditions are more equable the year around. The conditions of environment then are very favorable for the rapid growth of these plants. They develop in midwinter as well as in summer.

Mycelium of Coal Mine Fungi.—The mycelium of the mushrooms and bracket fungi grows in wonderful profusion in these abandoned coal mines. So far down in the moist earth the air in the tunnels or passages where the coal or rock has been removed is at all times nearly saturated with moisture. This abundance of moisture, with the favorable temperature, permits the mycelium to grow on the surface of the wood structures as readily as within the wood.

In the forest, while the air is damp at times, it soon dries out to such a degree that the mycelium can not exist to any great extent on the outer surface of the trunks and stumps, for it needs a great percentage of moisture for growth. The moisture, however, is abundant within the stumps or tree trunks, and the mycelium develops abundantly there.

So one can understand how it is that deep down in these abandoned mines the mycelium grows profusely on the surface of doors and wood props. Figure [11] is from a flashlight photograph, taken by the writer, of a beautiful growth on the surface of one of the doors in an abandoned coal mine at Wilkesbarre, Pa., during September, 1896. The specimen covered an area eight by ten feet on the surface of the door. The illustration shows very well the habit of growth of the mycelium. At the right is the advancing zone of growth, marked by several fan-shaped areas. At the extreme edge of growth the mycelium presents a delicate fringe of the growing ends where the threads are interlaced uniformly over the entire area. But a little distance back from the edge, where the mycelium is older, the threads are growing in a different way. They are now uniting into definite strands. Still further back and covering the larger part of the sheet of mycelium lying on the surface of the door, are numerous long, delicate tassels hanging downward. These were formed by the attempt on the part of the mycelium at numerous places to develop strands at right angles to the surface of the door. There being nothing to support them in their attempted aerial flight, they dangle downward in exquisite fashion. The mycelium in this condition is very soft and perishable. It disappears almost at touch.

On the posts or wood props used to support the rock roof above, the mycelium grows in great profusion also, often covering them with a thick white mantle, or draping them with a fabric of elegant texture. From the upper ends of the props it spreads out over the rock roof above for several feet in circumference, and beautiful white pendulous tassels remind one of stalactites.

Figure 12.—Agaricus campestris. Spore print. (Natural size.)

Direction in Growth of Mushrooms.—The direction of growth which these fungi take forms an interesting question for study. The common mushroom, the Agaricus, the amanitas, and other central stemmed species grow usually in an upright fashion; that is, the stem is erect. The cap then, when it expands, stands so that it is parallel with the surface of the earth. Where the cap does not fully expand, as in the campanulate forms, the pileus is still oriented horizontally, that is, with the gills downward. Even in such species, where the stems are ascending, the upper end of the stem curves so that the cap occupies the usual position with reference to the surface of the earth. This is beautifully shown in the case of those plants which grow on the side of trunks or stumps, where the stems could not well grow directly upward without hugging close to the side of the trunk, and then there would not be room for the expansion of the cap. This is well shown in a number of species of Mycena.

In those species where the stem is sub-central, i. e., set toward one side of the pileus, or where it is definitely lateral, the pileus is also expanded in a horizontal direction. From these lateral stemmed species there is an easy transition to the stemless forms which are sessile, that is, the shelving forms where the pileus is itself attached to the trunk, or other object of support on which it grows.

Where there is such uniformity in the position of a member or part of a plant under a variety of conditions, it is an indication that there is some underlying cause, and also, what is more important, that this position serves some useful purpose in the life and well being of the plant. We may cut the stem of a mushroom, say of the Agaricus campestris, close to the cap, and place the latter, gills downward, on a piece of white paper. It should now be covered securely with a small bell jar, or other vessel, so that no currents of air can get underneath. In the course of a few hours myriads of the brown spores will have fallen from the surface of the gills, where they are borne. They will pile up in long lines along on either side of all the gills and so give us an impression, or spore print, of the arrangement of the gills on the under side of the cap as shown in Fig. [12]. A white spore print from the smooth lepiota (L. naucina) is shown in Fig. [13]. This horizontal position of the cap then favors the falling of the spores, so that currents of air can scatter them and aid in the distribution of the fungus.

Figure 13.—Lepiota naucina. Spore print. (Natural size.)

But some may enquire how we know that there is any design in the horizontal position of the cap, and that there is some cause which brings about this uniformity of position with such entire harmony among such dissimilar forms. When a mushroom with a comparatively long stem, not quite fully matured or expanded, is pulled and laid on its side, or held in a horizontal position for a time, the upper part of the stem where growth is still taking place will curve upward so that the pileus is again brought more or less in a horizontal position.

Figure 14.—Amanita phalloides. Plant turned to one side by directive force of gravity, after having been placed in a horizontal position. (Natural size.)

In collecting these plants they are often placed on their side in the collecting basket, or on a table when in the study. In a few hours the younger, long stemmed ones have turned upward again. The plant shown in Fig. [14] (Amanita phalloides) was placed on its side in a basket for about an hour. At the end of the hour it had not turned. It was then stood upright in a glass, and in the course of a few hours had turned nearly at right angles. The stimulus it received while lying in a horizontal position for only an hour was sufficient to produce the change in direction of growth even after the upright position had been restored. This is often the case. Some of the more sensitive of the slender species are disturbed if they lie for only ten or fifteen minutes on the side. It is necessary, therefore, when collecting, if one wishes to keep the plants in the natural position for photographing, to support them in an upright position when they are being carried home from the woods.

The cause of this turning of the stem from the horizontal position, so that the pileus will be brought parallel with the surface of the earth, is the stimulus from the force of gravity, which has been well demonstrated in the case of the higher plants. That is, the force which causes the stems of the higher plants to grow upward also regulates the position of the cap of the pileated fungi. The reason for this is to be seen in the perfection with which the spores are shed from the surfaces of the gills by falling downward and out from the crevices between. The same is true with the shelving fungi on trees, etc., where the spores readily fall out from the pores of the honey-combed surface or from between the teeth of those sorts with a spiny under surface. If the caps were so arranged that the fruiting surface came to be on the upper side, the larger number of the spores would lodge in the crevices between the extensions of the fruiting surface. Singularly, this position of the fruiting surface does occur in the case of one genus with a few small species.

Interesting examples of the operation of this law are sometimes met with in abandoned coal mines, or more frequently in the woods. In abandoned mines the mushrooms sometimes grow from the mycelium which spreads out on the rock roof overhead. The rock roof prevents the plant from growing upright, and in growing laterally the weight of the plant together with the slight hold it can obtain on the solid rock causes it to hang downward. The end of the stem then curves upward so that the pileus is brought in a horizontal position. I have seen this in the case of Coprinus micaceus several times.

Figure 15.—Polyporus applanatus. From this view the larger cap is in the normal position in which it grew on the standing tree. Turn one fourth way round to the right for position of the plant after the tree fell. (1/6 natural size.)

In the woods, especially in the case of the perennial shelving fungi, interesting cases are met with. Figure [15] illustrates one of these peculiar forms of Polyporus (Fomes) applanatus. This is the species so often collected as a "curio," and on account of its very white under surface is much used for etching various figures. In the figure the larger cap which is horizontal represents the position of the plant when on the standing maple trunk. When the tree fell the shelf was brought into a perpendicular position. The fungus continued to grow, but its substance being hard and woody it cannot turn as the mushroom can. Instead, it now grows in such a way as to form several new caps, all horizontal, i. e., parallel with the surface of the earth, but perpendicular to the old shelf. If the page is turned one-fourth way round the figure will be brought in the position of the plant when it was growing on the fallen log.

Plate 3, Figure 16.—Dædalea ambigua. Upper right-hand shows normal plant in normal position when on tree. Upper left-hand shows abnormal plant with the large cap in normal position when growing on standing tree. Lower plant shows same plant in position after the tree fell, with new caps growing out in horizontal direction. (Lower plant 1/2 natural size.)

Another very interesting case is shown in the ambiguous trametes (Trametes ambigua), a white shelving fungus which occurs in the Southern States. It is shown in Fig. [16]. At the upper right hand is shown the normal plant in the normal position. At the upper left hand is shown an abnormal one with the large and first formed cap also in the normal position as it grew when the tree was standing. When the tree fell the shelf was on the upper side of the log. Now numerous new caps grew out from the edge as shown in the lower figure, forming a series of steps, as it were, up one side and down the other.

CHAPTER III.

GILL BEARING FUNGI: AGARICACEAE.[A]

The gill bearing fungi are known under the family Agaricaceæ, or popularly the agarics. They are distinguished by the fruiting area being distributed over the surface of plate-like or knife-like extensions or folds, usually from the under surface of the cap. These are known as the gills, or lamellæ, and they usually radiate from a common point, as from or near the stem, when the stem is present; or from the point of attachment of the pileus when the stem is absent. The plants vary widely in form and consistency, some being very soft and soon decaying, others turning into an inky fluid, others being tough and leathery, and some more or less woody or corky. The spores when seen in mass possess certain colors, white, rosy, brown or purple brown, black or ochraceous. While a more natural division of the agarics can be made on the basis of structure and consistency, the treatment here followed is based on the color of the spores, the method in vogue with the older botanists. While this method is more artificial, it is believed to be better for the beginner, especially for a popular treatment. The sections will be treated in the following order:

1. The purple-brown-spored agarics.
2. The black-spored agarics.
3. The white-spored agarics.
4. The rosy-spored agarics.
5. The ochre-spored agarics.

FOOTNOTES:

[A] For analytical keys to the families and genera see Chapter [XXIV].

CHAPTER IV.

THE PURPLE-BROWN-SPORED AGARICS.[B]

The members of this subdivision are recognized at maturity by the purple-brown, dark brown or nearly black spores when seen in mass. As they ripen on the surface of the gills the large number give the characteristic color to the lamellæ. Even on the gills the purple tinge of the brown spores can often be seen. The color is more satisfactorily obtained when the spores are caught in mass by placing the cap, gills downward, on white paper.

AGARICUS Linn. (PSALLIOTA Fr.)

In the genus Agaricus the spores at maturity are either purple-brown in mass or blackish with a purple tinge. The annulus is present on the stem, though disappearing soon in some species, and the stem is easily separated from the substance of the pileus. The gills are free from the stem, or only slightly adnexed. The genus is closely related to Stropharia and the species of the two genera are by some united under one genus (Psalliota, Hennings). Peck, 36th Report, N. Y. State Mus., p. 41–49, describes 7 species. Lloyd Mycol. Notes, No. 4, describes 8 species. C. O. Smith, Rhodora, I: 161–164, 1899, describes 8 species.

Agaricus (Psalliota) campestris Linn. Edible.—This plant has been quite fully described in the treatment of the parts of the mushroom, and a recapitulation will be sufficient here. It grows in lawns, pastures, by roadsides, and even in gardens and cultivated fields. A few specimens begin to appear in July, it is more plentiful in August, and abundantly so in September and October. It is 5–8 cm. high (2–3 inches), the cap is 5–12 cm. broad, and the stem 8–12 mm. in thickness.

The pileus is first rounded, then convex and more or less expanded. The surface at first is nearly smooth, presenting a soft, silky appearance from numerous loose fibrils. The surface is sometimes more or less torn into triangular scales, especially as the plants become old. The color is usually white, but varies more or less to light brown, especially in the scaly forms, where the scales may be quite prominent and dark brown in color. Sometimes the color is brownish before the scales appear. The flesh is white. The gills in the young button stage are white. They soon become pink in color and after the cap is expanded they quickly become purple brown, dark brown, and nearly black from the large number of spores on their surfaces. The gills are free from the stem and rounded behind (near the stem). The stem is white, nearly cylindrical, or it tapers a little toward the lower end. The flesh is solid, though the central core is less firm. The veil is thin, white, silky, and very frail. It is stretched as the cap expands and finally torn so that it clings either as an annulus around the stem, or fragments cling around the margin of the cap. Since the annulus is so frail it shrivels as the plant ages and becomes quite inconspicuous or disappears entirely (see Figs. 1–7).

Figure 17.—Agaricus rodmani. Entirely white, showing double veil or ring. (Natural size.) Copyright.

Variations in the surface characters of the cap and stem have led some to recognize several varieties. This is known as the common mushroom and is more widely known and collected for food than any other. It is also cultivated in mushroom houses, cellars, caves, abandoned mines, etc.

Agaricus (Psalliota) rodmani Pk. Edible.—Rodman's mushroom, Agaricus rodmani, grows in grassy places along streets of cities, either between the curbing and the walk, or between the curbing and the pavement. It is entirely white or whitish and sometimes tinged with yellowish at the center of the pileus. The plants are 4–8 cm. high, the cap 5–8 cm. broad and the stem 1–2 cm. in thickness.

Figure 18.—Agaricus arvensis, fairy ring.

The pileus is rounded, and then convex, very firm, compact and thick, with white flesh. The gills are crowded, first white, then pink, and in age blackish brown. The stem is very short, solid, nearly cylindrical, not bulbous. The annulus is quite characteristic, being very thick, with a short limb, and double, so that it often appears as two distinct rings on the middle or lower part of the stem as shown in Fig. [17]. This form of the annulus is probably due to the fact that the thick part of the margin of the pileus during the young stage rests between the lower and upper part of the annulus, i. e., the thick veil is attached both to the inner and outer surface of the margin of the cap, and when it is freed by the expansion of the pileus it remains as a double ring. It is eagerly sought and much relished by several persons at Ithaca familiar with its edible qualities.

The plant closely resembles A. campestris var., edulis, Vittad. (See Plate 54, Bresadola, I Funghi Mangerecci e Velenosi, 1899) and is probably the same.

Figure 19.—Agaricus silvicola. White to cream color, or yellow stains. (Natural size.) Copyright.

Agaricus (Psalliota) arvensis Schaeff. Edible.—The field mushroom, or horse mushroom, Agaricus arvensis, grows in fields or pastures, sometimes under trees and in borders of woods. One form is often white, or yellowish white, and often shows the yellow color when dried. The plant sometimes occurs in the form of a fairy ring as shown in Fig. [18]. It is 5–12 cm. high, the cap from 5–15 cm. broad and the stem 8–15 mm. in thickness.

The pileus is smooth, quite thick and firm, convex to expanded. The gills are first white, then tinged with pink and finally blackish brown. The stem is stout, nearly cylindrical, hollow, bulbous. The veil is double like that of Agaricus placomyces, the upper or inner layer remaining as a membrane, while the lower or outer layer is split radially and remains in large patches on the lower surface of the upper membrane.

Figure 20.—Agaricus silvicola, showing radiately torn lower part of veil. (Natural size.) Copyright.

Agaricus (Psalliota) silvicola Vittad. Edible.—The Agaricus silvicola grows in woods, groves, etc., on the ground, and has been found also in a newly made garden in the vicinity of trees near the woods. It is an attractive plant because of its graceful habit and the delicate shades of yellow and white. It ranges from 10–20 cm. high, the cap is 5–12 cm. broad and the stem 6–10 mm. in thickness.

The pileus becomes convex, and expanded or nearly flat, and often with an elevation or umbo in the center. It is thin, smooth, whitish and often tinged more or less deeply with yellow (sulfur or ochraceous) and is sometimes tinged with pink in the center. The flesh is whitish or tinged with pink. The gills when very young are whitish, then pink, and finally dark brown or blackish brown, much crowded, and distant from the stem. The stem is long, nearly cylindrical, whitish, abruptly enlarged below into a bulb. It is often yellowish below, and especially in drying becomes stained with yellow. The ring is thin, membranaceous, delicate, sometimes with broad, soft, floccose patches on the under side. The ring usually appears single, but sometimes the veil is seen to be double, and the outer or lower portion tends to split radially as in A. arvensis or A. placomyces. This is well shown in large specimens, and especially as the veil is stretched over the gills as shown in Fig. [20].

From the form of the plant as well as the peculiarities of the veil in the larger specimens, it is related to A. arvensis and A. placomyces, more closely to the former. It occurs during mid-summer and early autumn. Figure 10 is from plants (No. 1986 C. U. herbarium) collected in open woods at Ithaca.

Plate 4.—Agaricus placomyces. Figure 21.—Upper view of cap, side view of stem. Figure 22.—Under view of plant showing radiately torn under side of the double veil. (3/4 natural size.) Copyright.

Plate 5, Figure 23.—Agaricus placomyces. Three different views, see text for explanations. Dark scales on cap. (Natural size.) Copyright.

Agaricus (Psalliota) subrufescens Pk. Edible.—The Agaricus subrufescens was described by Dr. Peck from specimens collected on a compost heap composed chiefly of leaves, at Glen Cove, Long Island. It occurs sometimes in greenhouses. In one case reported by Peck it appeared in soil prepared for forcing cucumbers in a greenhouse in Washington, D. C.

According to the description the pileus becomes convex or broadly expanded, is covered with silky hairs and numerous minute scales. The color is whitish, grayish or dull reddish brown, the center being usually smooth and darker, while the flesh is white. The gills change from white to pinkish and blackish brown in age. The stem is long, nearly cylindrical or somewhat enlarged or bulbous at the base, first stuffed, then hollow, white. The annulus is thick, and the under side marked by loose threads or scales.

This plant is said to differ from the common mushroom (A. campestris) in the more deeply hemispherical cap of the young plant, the hollow and somewhat bulbous stem, and in the scales on the under side of the annulus. In fresh plants the flesh has also a flavor of almonds. It is closely related to A. silvaticus Schaeff., p. 62, T. 242, Icones Fung. Bav. etc., 1770, if not identical with it. A. silvaticus has light ochraceous or subrufescent scales on the cap, a strong odor, and occurs in gardens as well as in the woods.

Agaricus (Psalliota) fabaceus Berk., was described in Hooker's London Journal of Botany, 6: 314, 1847, from specimens collected in Ohio. The plant is white and is said to have a strong but not unpleasant odor. Agaricus amygdalinus Curt., from North Carolina, and of which no description was published, was so named on account of the almond-like flavor of the plant. Dr. Farlow suggests (Proc. Bost. Soc. Nat. Hist. 26: 356–358, 1894) that A. fabaceus, amygdalinus, and subrufescens are identical.

Agaricus (Psalliota) placomyces Pk. Edible.—The flat-cap mushroom, Agaricus placomyces Pk., occurs in borders of woods or under trees from June to September. According to Peck it occurs in borders of hemlock woods, or under hemlock trees. At Ithaca it is not always associated with hemlock trees. The largest specimens found here were in the border of mixed woods where hemlock was a constituent. It has been found near and under white pine trees in lawns, around the Norway spruce and under the Norway spruce. The plants are from 5–15 cm. high, the cap from 5–12 cm. in diameter, and the stem 6–8 mm. in thickness.

The pileus when young is broadly ovate, then becomes convex or fully expanded and flat in age, and is quite thin. The ground color is whitish, often with a yellowish tinge, while the surface is ornamented with numerous minute brownish scales which are scattered over a large part of the cap, but crowded or conjoined at the center into a large circular patch. This gives to the plant with its shapely form a beautiful appearance. In the young stage the entire surface of the pileus is quite evenly brown. As it expands the outer brown portion is torn asunder into numerous scales because the surface threads composing this brown layer cease to grow. These scales are farther apart toward the margin of the cap, because this portion of the cap always expands more than the center, in all mushrooms. The gills are at first white, or very soon pink in color, and in age are blackish brown. Spores 5–8 × 3–4 µ.

The stem is nearly cylindrical, hollow or stuffed, white or whitish, smooth, bulbous, and the bulb is sometimes tinged with yellow. The veil is very handsome, and the way in which the annulus is formed from it is very interesting. The veil is quite broad, and it is double, that is, it consists of two layers which are loosely joined by threads. In the young stage the veil lies between the gills and the lower two-thirds of the stem. As the pileus expands the lower (outer part) layer of the veil is torn, often in quite regular radiating portions, as shown in Fig. [22]. An interesting condition of the veil is shown in the middle plant in Fig. 23. Here the outer or lower layer of the veil did not split radially, but remained as a tube surrounding the stem, while the two layers were separated, the inner one being still stretched over the gills. It is customary to speak of the lower part of the veil as the outer part when the cap is expanded and the veil is still stretched across over the gills, while the upper portion is spoken of as the inner layer or part. It is closely related to A. arvensis, and may represent a wood inhabiting variety of that species.

Agaricus (Psalliota) comtulus Fr.—This pretty little agaric seems to be rather rare. It was found sparingly on several occasions in open woods under pines at Ithaca, N. Y., during October, 1898. Lloyd reports it from Ohio (Mycolog. Notes, No. 56, Nov. 1899), and Smith from Vermont (Rhodora I, 1899). Fries' description (Epicrisis, No. 877) runs as follows: "Pileus slightly fleshy, convex, plane, obtuse, nearly smooth, with appressed silky hairs, stem hollow, sub-attenuate, smooth, white to yellowish, annulus fugacious; gills free, crowded, broad in front, from flesh to rose color. In damp grassy places. Stem 2 inches by 2 lines, at first floccose stuffed. Pileus 1–1-1/2 inch diameter. Color from white to yellowish."

Figure 24.—Agaricus comtulus (natural size, sometimes larger). Cap creamy white with egg-yellow stains, smoky when older. Stem same color; gills grayish, then rose, then purple brown. Copyright.

The plants collected at Ithaca are illustrated in Fig. [24] from a photograph of plants (No. 2879 C. U. herbarium). My notes on these specimens run as follows: Plant 3–6 cm. high, pileus 1.5–3 cm. broad, stem 3–4 mm. in thickness. Pileus convex to expanded, fleshy, thin on the margin, margin at first incurved, creamy white with egg yellow stains, darker on the center, in age somewhat darker to umber or fuliginous, moist when fresh, surface soon dry, flesh tinged with yellow. The gills are white when young, then grayish to pale rose, and finally light purple brown, rounded in front, tapering behind (next the stem) and rounded, free from the stem, 4–5 mm. broad. Basidia clavate, 25–30 × 5–6 µ. Spores small, oval, 3–4 × 2–3 µ, in mass light purple brown. The stem tapers above, is sub-bulbous below, yellowish and stained with darker yellowish threads below the annulus, hollow, fibrous, fleshy. The veil whitish stained with yellow, delicate, rupturing irregularly, portions of it clinging to margin of the pileus and portions forming a delicate ring. When parts of the plant come in contact with white paper a blue stain is apt to be imparted to the paper, resembling the reaction of iodine on starch. This peculiarity has been observed also in the case of another species of Agaricus. The species is regarded with suspicion by some. I collected the plant also at Blowing Rock, N. C., in September, 1899. The caps of these specimens measure 4 cm. in diameter.

Agaricus diminutivus Pk., is a closely related species. It is distinguished chiefly by its somewhat larger size, and purplish to reddish brown hairs on the surface of the pileus, and by the somewhat larger spores, which, however, are small. I have found it at Ithaca, the surface of the pileus hairy, with beautiful, triangular, soft, appressed, purplish scales.

HYPHOLOMA Fr.

In the genus Hypholoma the spores are purple brown, the gills attached to the stem, and the veil when ruptured clings to the margin of the cap instead of to the stem, so that a ring is not formed, or only rarely in some specimens. The stem is said to be continuous with the substance of the cap, that is, it is not easily separated from it. The genus is closely related to Agaricus (Psalliota) and Stropharia, from both of which it differs in the veil not forming a ring, but clinging to the margin of the cap. It further differs from Agaricus in the stem being continuous with the substance of the cap, while Stropharia seems to differ in this respect in different species. The plants grow both on the ground and on wood. There are several species which are edible and are very common. Peck gives a synopsis of six species in the 49th Report New York State Mus., page 61, 1896, and Morgan describes 7 species in Jour. Cinn. Soc. Nat. Hist. 6: 113–115.

Hypholoma sublateritium Schaeff. Edible, bitter sometimes. The name of this species is derived from the color of the cap, which is nearly a brick red color, sometimes tawny. The margin is lighter in color. The plants grow usually in large clusters on old stumps or frequently appearing on the ground from buried portions of stumps or from roots. There are from six to ten, or twenty or more plants in a single cluster. A single plant is from 8–12 cm. high, the cap is 5–8 cm. broad, and the stem 6–8 mm. in thickness.

The pileus is convex to expanded, smooth, or sometimes with loose threads from the veil, especially when young, even, dry. The flesh is firm, whitish, and in age becoming somewhat yellowish. The gills are adnate, sometimes decurrent by a little tooth, rather crowded, narrow, whitish, then dull yellow, and becoming dark from the spores, purplish to olivaceous. The stem usually tapers downward, is firm, stuffed, smooth, or with remnants of the veil giving it a floccose scaly appearance, usually ascending because of the crowded growth. The veil is thin and only manifested in the young stage of the plant as a loose weft of threads. As the cap expands the veil is torn and adheres to the margin, but soon disappears.

Plate 6, Figure 25.—Hypholoma sublateritium. Cap brick-red or tawny. (Natural size, often larger.) Copyright.

Plate 7, Figure 26.—Hypholoma appendiculatum (natural size, often larger). White floccose scales on cap (var. coroniferum) and appendiculate veil; caps whitish or brown, tawny, or tinge of ochre. Gills white, then purple-brown. Copyright.

The flesh of this plant is said by European writers to be bitter to the taste, and it is regarded there as poisonous. This character seems to be the only distinguishing one between the Hypholoma sublateritium Schaeff., of Europe, and the Hypholoma perplexum Pk., of this country which is edible, and probably is identical with H. sublateritium. If the plant in hand agrees with this description in other respects, and is not bitter, there should be no danger in its use. According to Bresadola, the bitter taste is not pronounced in H. sublateritium. The taste probably varies as it does in other plants. For example, in Pholiota præcox, an edible species, I detected a decided bitter taste in plants collected in June, 1900. Four other persons were requested to taste the plants. Two of them pronounced them bitter, while two did not detect the bitter taste.

There is a variety of Hypholoma sublateritium, with delicate floccose scales in concentric rows near the margin of the cap, called var. squamosum Cooke. This is the plant illustrated in Fig. [25], from specimens collected on rotting wood in the Cascadilla woods, Ithaca, N. Y. It occurs from spring to autumn.

Hypholoma epixanthum Fr., is near the former species, but has a yellow pileus, and the light yellow gills become gray, not purple.

Hypholoma appendiculatum Bull. Edible.—This species is common during late spring and in the summer. It grows on old stumps and logs, and often on the ground, especially where there are dead roots. It is scattered or clustered, but large tufts are not formed as in H. sublateritium. The plants are 6–8 cm. high, the cap 5–7 cm. broad, and the stem 4–6 mm. in thickness.

The pileus is ovate, convex to expanded, and often the margin elevated, and then the cap appears depressed. It is fleshy, thin, whitish or brown, tawny, or with a tinge of ochre, and becoming pale in age and when dry. As the plant becomes old the pileus often cracks in various ways, sometimes splitting radially into several lobes, and then in other cases cracking into irregular areas, showing the white flesh underneath. The surface of the pileus when young is sometimes sprinkled with whitish particles giving it a mealy appearance. The gills are attached to the stem, crowded, becoming more or less free by breaking away from the stem, especially in old plants. They are white, then flesh colored, brownish with a slight purple tinge. The stem is white, smooth, or with numerous small white particles at the apex, becoming hollow. The veil is very delicate, white, and only seen in quite young plants when they are fresh. It clings to the margin of the cap for a short period, and then soon disappears.

Figure 27.—Hypholoma appendiculatum (natural size), showing appendiculate veil. Copyright.

Sometimes the pileus is covered with numerous white, delicate floccose scales, which give it a beautiful appearance, as in Fig. [26], from specimens (No. 3185 C. U. herbarium), collected on the campus of Cornell University among grass. The entire plant is very brittle, and easily broken. It is tender and excellent for food. I often eat the caps raw.

Hypholoma candolleanum Fr., occurs in woods on the ground, or on very rotten wood. It is not so fragile as H. appendiculatum and the gills are dark violaceous, not flesh color as they are in H. appendiculatum when they begin to turn, and nearly free from the stem.

Hypholoma lacrymabundum Fr.—This plant was found during September and October in wet grassy places in a shallow ditch by the roadside, and in borders of woods, Ithaca, N. Y., 1898. The plants are scattered or clustered, several often joined at the base of the stem. They are 4–8 cm. high, the cap 2–5 cm. broad, and the stem 4–8 mm. in thickness.

Figure 28.—Hypholoma lacrymabundum (natural size). Cap and stem tawny or light yellowish, with intermediate shades or shades of umber, surface with soft floccose scales. Copyright.

The pileus is convex to expanded, sometimes broadly umbonate in age, and usually with radiating wrinkles extending irregularly. On the surface are silky or tomentose threads not much elevated from the surface, and as the plant ages these are drawn into triangular scales which are easily washed apart by the rains. The color is tawny or light yellowish with intermediate shades, darker on the umbo and becoming darker in age, sometimes umber colored, and stained with black, especially after rains where the spores are washed on the pileus. The flesh is tinged with light yellow, or tawny, or brown, soft, and easily broken. The gills are sinuate, adnate, somewhat ventricose, very rarely in abnormal specimens anastomosing near the margin of the pileus, at first light yellowish, then shading to umber and spotted with black and rusty brown as the spores mature, easily breaking away from the stipe, whitish on the edge. Drops of moisture sometimes are formed on the gills. Basidia abruptly clavate, 30–35 × 10–12 µ. Cystidia hyaline, thin walled, projecting above the hymenium 40 µ, and 14–15 µ broad. Spores black, purple tinged, broadly elliptical and somewhat curved, 9–11 × 7–8 µ.

The stem is fleshy to fibrous, the same color as the pileus, floccose scaly more or less up to the veil, smooth or white pruinose above the veil, straight or curved, somewhat striate below.

The veil in young plants is hairy, of the same texture as the surface of the pileus, torn and mostly clinging to the margin of the pileus, and disappearing with age.

The general habit and different stages of development as well as some of the characters of the plant are shown in Fig. [28] (No. 4620 Cornell University herbarium). The edible qualities of this plant have not been tested.

Hypholoma rugocephalum Atkinson.—This interesting species grows in damp places in woods. The plants are tufted or occur singly. They are 8–12 cm. high, the cap 6–10 cm. broad, and the stem 6–10 mm. in thickness.

The pileus is convex to expanded, and the margin at last revolute (upturned). The surface is marked by strong wrinkles (rugæ), which radiate irregularly from the center toward the margin. The pileus is broadly umbonate, fleshy at the center and thinner toward the margin, the flesh tinged with yellow, the surface slightly viscid, but not markedly so even when moist, smooth, not hairy or scaly, the thin margin extending little beyond ends of the gills. The color is tawny (near fulvus). The gills are adnate, slightly sinuate, 5–7 mm. broad, in age easily breaking away from the stem and then rounded at this end, spotted with the black spores, lighter on the edge. The spores are black in mass (with a suggestion of a purple tinge), oval to broadly elliptical, inequilateral, pointed at each end, echinulate, or minutely tuberculate, 8–11 × 6–8 µ. The basidia are short, cylindrical; cystidia cylindrical, somewhat enlarged at the free end, hyaline, delicate, thin-walled, in groups of two to six or more (perhaps this is partly responsible for the black spotted condition of the gills). The stem is cylindrical, even, somewhat bulbous, of the same color as the pileus, but lighter above the annulus, irregular, smooth, fleshy, hollow, continuous with the substance of the pileus. The annulus is formed of a few threads, remnants of the veil, which are stained black by the spores. Figure [29] is from plants (No. 3202 C. U. herbarium) collected near Ithaca, July 18, 1899.

Plate 8, Figure 29.—Hypholoma rugocephalum (7/8 natural size). Cap tawny, gills purple black, spotted. Copyright.

STROPHARIA Fr.

The genus Stropharia has purple-brown spores, the gills are attached to the stem, and the veil forms a ring on the stem.

Figure 30.—Stropharia semiglobata (natural size). Cap and stem light yellow, viscid, gills brownish purple. Copyright.

Stropharia semiglobata Batsch.—This species is rather common and widely distributed, occurring in grassy places recently manured, or on dung. The plants are scattered or clustered, rarely two or three joined at the base. They are 5–12 cm. high, the cap 1–3 cm. broad, and the stems 2–4 mm. in thickness. The entire plant is light yellow, and viscid when moist, the gills becoming purplish brown, or nearly black. Stevenson says it is regarded as poisonous.

The pileus is rounded, then hemispherical (semi-globate), smooth, fleshy at the center, thinner toward the margin, even, very viscid or viscous when moist, light yellow. The gills are squarely set against the stem (adnate), broad, smooth, in age purplish brown to blackish, the color more or less clouded. The spores in mass, are brownish purple. The stem is slender, cylindrical, becoming hollow, straight, even or bulbous below, yellowish, but paler at the apex where there are often parallel striæ, marks from the gills in the young stage. The stem is often viscid and smeared with the glutinous substance which envelopes the plant when young, and from the more or less glutinous veil. The ring is glutinous when moist.

Figure [30] is from plants (No. 4613 C. U. herbarium) collected on one of the streets of Ithaca.

Stropharia stercoraria Fr., is a closely related plant, about the same size, but the pileus, first hemispherical, then becoming expanded and sometimes striate on the margin, while the stem is stuffed. The gills are said to be of one color and the ring floccose, viscose, and evanescent in drying. It occurs on dung, or in grassy places recently manured.

Stropharia æruginosa Curt., the greenish Stropharia, is from 6–8 cm. high, and the pileus 5–7 cm. broad. The ground color is yellowish, but the plant is covered with a greenish slime which tends to disappear with age. It is found in woods and open places during late summer and in autumn. According to Stevenson it is poisonous.

FOOTNOTES:

[B] For analytical key to the genera see Chapter [XXIV].

CHAPTER V.

THE BLACK-SPORED AGARICS.

The spores are black in mass, not purple tinged. For analytical keys to the genera see Chapter [XXIV].

COPRINUS Pers.

The species of Coprinus are readily recognised from the black spores in addition to the fact that the gills, at maturity, dissolve into a black or inky fluid. The larger species especially form in this way an abundance of the black fluid, so that it drops from the pileus and blackens the grass, etc., underneath the plant. In some of the smaller species the gills do not wholly deliquesce, but the cap splits on top along the line of the longer gills, this split passing down through the gill, dividing it into two thin laminæ, which, however, remain united at the lower edge. This gives a fluted appearance to the margin of the pileus, which is very thin and membranaceous.

Figure 31.—Coprinus comatus, "shaggy-mane," in lawn.

The plants vary in size, from tiny ones to those which are several inches high and more than an inch broad. Their habitat (that is, the place where they grow) is peculiar. A number of the species grow on dung or recently manured ground. From this peculiarity the genus received the name Coprinus from the Greek word κοπρὁς, meaning dung. Some of the species, however, grow on decaying logs, on the ground, on leaves, etc.

Coprinus comatus Fr. Edible.—One of the finest species in this genus is the shaggy-mane, or horse-tail mushroom, as it is popularly called. It occurs in lawns and other grassy places, especially in richly manured ground. The plants sometimes occur singly, or a few together, but often quite large numbers of them appear in a small area. They occur most abundantly during quite wet weather, or after heavy rains, in late spring or during the autumn, and also in the summer. From the rapid growth of many of the mushrooms we are apt to be taken by surprise to see them all up some day, when the day before there were none. The shaggy-mane often furnishes a surprise of this kind. In our lawns we are accustomed to a pretty bit of greensward with clumps of shrubbery, and here and there the overhanging branches of some shade tree. On some fine morning when we find a whole flock of these shaggy-manes, which have sprung up during the night, we can imagine that some such kind of a surprise must have come to Browning when he wrote these words:

"By the rose flesh mushroom undivulged

Last evening. Nay, in to-day's first dew

Yon sudden coral nipple bulged,

Where a freaked, fawn colored, flaky crew

Of toadstools peep indulged."

Figure 32.—Coprinus comatus. "Buttons," some in section showing gill slits and hollow stem; colors white and black. (Natural size.)

The plant is called shaggy-mane because of the very shaggy appearance of the cap, due to the surface being torn up into long locks. The illustrations of the shaggy mane shown here represent the different stages of development, and the account here given is largely taken from the account written by me in Bulletin 168 of the Cornell University Agr. Exp. Station.

Figure 33.—Coprinus comatus (natural size).]

In Fig. [32] are shown two buttons of the size when they are just ready to break through the soil. They appear mottled with dark and white, for the outer layer of fungus threads, which are dark brown, is torn and separated into patches or scales, showing between the delicate meshes of white threads which lie beneath. The upper part of the button is already forming the cap, and the slight constriction about midway shows the lower boundary or margin of the pileus where it is still connected with the undeveloped stem.

At the right of each of these buttons in the figure is shown a section of a plant of the same age. Here the parts of the plant, though still undeveloped, are quite well marked out. Just underneath the pileus layer are the gills. In the section one gill is exposed to view on either side. In the section of the larger button the free edge of the gill is still closely applied to the stem, while in the small one the gills are separated a short distance from the stems showing "gill slits." Here, too, the connection of the margin of the pileus with the stem is still shown, and forms the veil. This kind of a veil is a marginal veil.

Figure 34.—Coprinus comatus (natural size). This one entirely white, none of the scales black tipped.

The stem is hollow even at this young stage, and a slender cord of mycelium extends down the center of the tube thus formed, as is shown in the sections.

The plants are nearly all white when full grown. The brown scales, so close together on the buttons, are widely separated except at the top or center of the pileus, where they remain close together and form a broad cap.

A study of the different stages, which appear from the button stage to the mature plant, reveals the cause of this change in color and the wide separation of the dark brown scales. The threads of the outer layer of the pileus, and especially those in the brown patches seen on the buttons, soon cease to grow, though they are firmly entangled with the inner layers. Now the threads underneath and all through the plant, in the gills and in the upper part of the stem, grow and elongate rapidly. This pulls on the outer layer, tearing it in the first place into small patches, and causing them later to be more widely separated on the mature plant. Some of these scales remain quite large, while others are torn up into quite small tufts.

Figure 35.—Coprinus comatus, sections of the plants in Fig. [33] (natural size).

As the plant ages, the next inner layers of the pileus grow less rapidly, so that the white layer beneath the brown is torn up into an intricate tangle of locks and tufts, or is frazzled into a delicate pile which exists here and there between well formed tufts. While all present the same general characters there is considerable individual variation, as one can see by comparing a number of different plants. Figure [34] shows one of the interesting conditions. There is little of the brown color, and the outer portion of the pileus is torn into long locks, quite evenly distributed and curled up at the ends in an interesting fashion which merits well the term "shaggy." In others the threads are looped up quite regularly into triangular tresses which appear to be knotted at the ends where the tangle of brown threads holds them together.

Figure 36.—Coprinus comatus, early stages of deliquescence; the ring is lying on the sod (natural size).

There is one curious feature about the expansion of the pileus of the shaggy-mane which could not escape our attention. The pileus has become very long while comparatively little lateral expansion has taken place. The pileus has remained cylindrical or barrel-shaped, while in the case of the common mushroom the pileus expands into the form of an umbrella.

Figure 37.—Coprinus comatus, later stage of deliquescence, pileus becoming more expanded (natural size).

The cylindrical or barrel-shaped pileus is characteristic of the shaggy-mane mushroom. As the pileus elongates the stem does also, but more rapidly. This tears apart the connection of the margin of the pileus with the base of the stem, as is plainly shown in Fig. [33]. In breaking away, the connecting portion or veil is freed both from the stem and from the margin of the pileus, and is left as a free, or loose, ring around the stem. In the shaggy-mane the veil does not form a thin, expanded curtain. It is really an annular outer layer of the button lying between the margin of the cap and the base of the stem. It becomes free from the stem. As the stem elongates more rapidly than the cap, the latter is lifted up away from the base of the stem. Sometimes the free ring is left as a collar around the base of the stem, still loosely adherent to the superficial layer of the same, or it remains for a time more or less adherent to the margin of the pileus as shown in the plant at the left hand in Fig. [33]. It is often lifted higher up on the stem before it becomes free from the cap, and is then left dangling somewhere on the stem, or it may break and fall down on the sod. In other instances it may remain quite firmly adherent to the margin of the pileus so that it breaks apart as the pileus in age expands somewhat. In such cases one often searches for some time to discover it clinging as a sterile margin of the cap. It is interesting to observe a section of the plants at this stage. These sections can be made by splitting the pileus and stem lengthwise through the middle line with a sharp knife, as shown in Fig. [35]. Here, in the plant at the right hand, the "cord" of mycelium is plainly seen running through the hollow stem. The gills form a large portion of the plant, for they are very broad and lie closely packed side by side. They are nowhere attached to the stem, but at the upper end round off to the cap, leaving a well defined space between their ends and the stem. The cap, while it is rather thick at the center, i. e., where it joins the stem, becomes comparatively thin where it spreads out over the gills. At this age of the plant the gills are of a rich salmon color, i. e., before the spores are ripe, and the taste when raw is a pleasant nutty flavor, reminding one of the meat of fresh green hickory nuts. In a somewhat earlier stage the edges of all the gills are closely applied to the stem which they surround. So closely are they applied to the stem in most cases that threads of mycelium pass from the stem to the edge of the gills. As the cap expands slightly in ageing, these threads are torn asunder and the stem is covered with a very delicate down or with flocculent particles which easily disappear on handling or by the washing of the rains. The edges of the gills are also left in a frazzled condition, as one can see by examining them with a good hand lens.

The spores now begin to ripen and as they become black the color of the gills changes. At the same time the gills and the cap begin to dissolve into an inky fluid, first becoming dark and then melting into a black liquid. As this accumulates it forms into drops which dangle from the cap until they fall away. This change takes place on the margin of the cap first, and advances toward the center, and the contrast of color, as the blackening invades the rich salmon, is very striking. The cap now begins to expand outward more, so that it becomes somewhat umbrella shaped. The extreme outer surface does not dissolve so freely, and the thin remnant curls upward and becomes enrolled on the upper side as the cap with wasted gills becomes nearly flat.

Coprinus atramentarius (Bull.) Fr. Edible.—The ink-cap (Coprinus atramentarius) occurs under much the same conditions as the shaggy-mane, and is sometimes found accompanying it. It is usually more common and more abundant. It springs up in old or newly made lawns which have been richly manured, or it occurs in other grassy places. Sometimes the plants are scattered, sometimes two or three in a cluster, but usually large clusters are formed where ten to twenty or more are crowded closely together (Fig. [39]). The stems are shorter than those of the shaggy-mane and the cap is different in shape and color. The cap is egg-shaped or oval. It varies in color from a silvery grey, in some forms, to a dark ashen grey, or smoky brown color in others. Sometimes the cap is entirely smooth, as I have seen it in some of the silvery grey forms, where the delicate fibres coursing down in lines on the outer surface cast a beautiful silvery sheen in the light. Other forms present numerous small scales on the top or center of the cap which are formed by the cleavage of the outer surface here into large numbers of pointed tufts. In others, the delicate tufts cover more or less the entire surface, giving the plant a coarsely granular aspect. This is perhaps the more common appearance, at least so far as my observation goes. But not infrequently one finds forms which have the entire outer surface of the cap torn into quite a large number of coarse scales, and these are often more prominent over the upper portion. Fine lines or striations mark also the entire surface of all the forms, especially toward the margin, where the scales are not so prominent. The marginal half of the cap is also frequently furrowed more or less irregularly, and this forms a crenate or uneven edge.

Plate 9, Figure 38. Coprinus comatus, drops of inky fluid about to fall from wasted pileus (natural size).

Plate 10, Figure 39.—Coprinus atramentarius, nearly smooth form, gray color (natural size)

Figure 40.—Coprinus atramentarius, scaly form (natural size).

The annulus or ring on the stem of the ink-cap is very different from that of the shaggy-mane. It forms an irregularly zigzag elevated line of threads which extend around the stem near the base. It is well shown in Fig. [41] as a border line between the lower scaly end of the stem and the smooth white upper part. It is formed at the time of the separation of the margin of the cap from the stem, the connecting fibres being pulled outward and left to mark the line of junction, while others below give the scaly appearance. It is easily effaced by rough handling or by the washing of the rains. A section of a plant is illustrated by a photograph in Fig. [42]. On either side of the stem is shown the layer of fibres which form the annulus, and this layer is of a different texture from that of the stem. The stem is hollow as seen here also. In this figure one can see the change in color of the gills just at the time when they begin to deliquesce. This deliquescence proceeds much in the same way as in the shaggy-mane, and sometimes the thin remnant of the cap expands and the margin is enrolled over the top.

Figure 41.—Coprinus atramentarius, showing annulus as border line between scaly and smooth part of the stem (natural size).

Coprinus micaceus (Bull.) Fr. Edible.—The glistening coprinus received its name because of the very delicate scales which often cover the surface of the cap, and glisten in the light like particles of mica. This plant is very common during the spring and early summer, though it does appear during the autumn. It occurs about the bases of stumps or trees or in grassy or denuded places, from dead roots, etc., buried in the soil. It occurs in dense tufts of ten to thirty or more individuals; sometimes as many as several hundred spring up from the roots of a dead tree or stump along the streets or in lawns, forming large masses. More rarely it occurs on logs in the woods, and sometimes the plants are scattered in lawns. From the different habits of the plant it is sometimes difficult to determine, especially where the individuals are more or less scattered. However, the color, and the markings on the cap, especially the presence of the small shining scales when not effaced, characterize the plant so that little difficulty is experienced in determining it when one has once carefully noted these peculiarities.

Figure 42.—Coprinus atramentarius, section of one of the plants in Fig. [41] (natural size).