START OF THE PROJECT GUTENBERG EBOOK STUDIES OF AMERICAN FUNGI. MUSHROOMS, EDIBLE, POISONOUS, ETC.*** E-text prepared by Peter Vachuska, Chuck Greif, Leonard Johnson, and the Project Gutenberg Online Distributed Proofreading Team (https://www.pgdp.net) Note: Project Gutenberg also has an HTML version of this file which includes the original illustrations. See 26492-h.htm or 26492-h.zip: (https://www.gutenberg.org/dirs/2/6/4/9/26492/26492-h/26492-h.htm) or (https://www.gutenberg.org/dirs/2/6/4/9/26492/26492-h.zip) Transcriber's note: Text enclosed between equal signs was in bold face in the original (=bold=). An em-dash or double hyphen (--) is used in this e-text to indicate ranges. In chemical formulas, a subscriped number is preceded by and underscore (H_2O). A detailed transcriber's note is at the end of the text. 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 [Illustration: PLATE 1. FIG. 1.--Amanita muscaria. FIG. 2.--A. frostiana. Copyright 1900.] [Illustration: Printer's logo.] 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, Ithaca, N. Y., October, 1900. Cornell University. 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. PAGE Chapter I. Form and Characters of the Mushrooms, 1 Chapter II. Development of the Mushroom, 5 Chapter III. Gill Bearing Fungi; Agaricaceæ, 17 Chapter IV. The Purple-Brown-Spored Agarics, 18 Chapter V. The Black-Spored Agarics, 32 Chapter VI. The White-Spored Agarics, 52 Chapter VII. The Rosy-Spored Agarics, 138 Chapter VIII. The Ochre-Spored Agarics, 150 Chapter IX. The Tube Bearing Fungi; Polyporaceæ, 171 Chapter X. Hedgehog Fungi; Hydnaceæ, 195 Chapter XI. Coral Fungi; Clavariaceæ, 200 Chapter XII. The Trembling Fungi; Tremellineæ, 204 Chapter XIII. Thelephoraceæ, 208 Chapter XIV. Puff-Balls; Lycoperdaceæ, 209 Chapter XV. Stinkhorn Fungi; Phalloideæ, 213 Chapter XVI. Morels, Cup-Fungi, Helvellas, etc., Discomycetes, 216 Chapter XVII. Collection and Preservation of the Fleshy Fungi, 222 Chapter XVIII. Selection and Preparation of Mushrooms for the Table, 229 Chapter XIX. Uses of Mushrooms, 231 Fungi in the Arts, 234 Chapter XX. Cultivation of Mushrooms, 237 The Cave Culture of Mushrooms in America, 239 The House Culture of Mushrooms, 241 Curing the Manure, 247 Making up the Beds, 250 What Spawn Is, 255 Spawning the Beds, 263 Chapter XXI. Recipes for Cooking Mushrooms (Mrs. Sarah Tyson Rorer), 277 Chapter XXII. Chemistry and Toxicology of the Fungi (J. F. 288 Clark), Chapter XXIII. Description of Terms applied to Certain Structural Characters of Mushrooms (H. Hasselbring), 298 APPENDIX. Analytical Keys (The Author), 307 Glossary of Technical Terms (The Author), 313 Index to Genera and Illustrations, 315 Index to Species, 321 CORRECTIONS. Page 33, 10th line, for [Greek: _kornos_] read [Greek: _kopros_]. 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. [Illustration: 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. [Illustration: 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. [Illustration: 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. [Illustration: 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. [Illustration: 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. [Illustration: 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. [Illustration: 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. [Illustration: 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_. [Illustration: 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. [Illustration: 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. [Illustration: 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. [Illustration: 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. [Illustration: 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. [Illustration: 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. [Illustration: 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. [Illustration: 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). [Illustration: 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. [Illustration: 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. [Illustration: 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. [Illustration: 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. [Illustration: FIGURE 21. FIGURE 22. 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.] [Illustration: 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,
{'title': 'Studies of American Fungi. Mushrooms, Edible, Poisonous, etc. by Atkinson', 'source': 'Project Gutenberg', 'lang': 'en'}