Popular Science Monthly/Volume 7/June 1875/Toadstools and their Kindred
|TOADSTOOLS AND THEIR KINDRED.|
IN taking "toadstools" as the text of a little botanical discourse, we start with a familiar notion if not a scientific one; but all science begins with common ideas which it corrects, extends, and develops. Everybody knows what toadstools are, odd-looking things that grow up in the fields and are often kicked aside in rural rambles, of no use to man or beast, and "pizen" to eat. This is the oldest, the widest, and the lowest state of mind upon the subject. But many have got beyond this, and recognize that some of these queer-looking things are actually eatable; these they distinguish as mushrooms, and all the rest are lumped together as toadstools. A step forward, and we become slightly scientific; that is, the different kinds begin to be noted, and compared, and classed with reference to their particular characters. When so much is gained, it soon appears that the subject is much wider than was supposed, and that all these growths are but parts of an extensive division of peculiar plants called fungi; and, having reached this state of intelligence, toadstools have disappeared. While, then, the popular term may answer to indicate generally what we are talking about, it conveys no exact meaning. The group of plants represented upon the plate is not merely a family of toadstools, but a collection of fungi. By their unlike characters they belong to separate groups in this class, and each has its separate name; for nomenclature must keep pace with science, and its higher discriminations require separate technical terms to mark them. Some people cry out against a few strange words in botany, and make it an excuse for neglecting the study; but the real reason is, a lack of interest in the knowledge of Nature, for they are generally ready enough to spend whole years in the acquisition of strange words by the thousand in. foreign languages, living and dead. Scientific terms have an educational value, because they involve and give precision to new ideas, while in acquiring an additional language we are only obtaining new terms for old ideas.
Of all the common objects of the country, toadstools seem to be least related to surrounding things. Neither in form, nor color, nor apparent origin, nor distinguishable parts, do they resemble other plants; and scientific scrutiny must replace common observation before the first step in their classification can be taken. At the very outset of study the botanist is struck by their paradoxical character. In rapidity of growth and speedy decay they are more allied to low animal than to vegetal forms. Like animals, they feed upon organic matter. Their substance is rich in nitrogen, has a savory meat-like taste, and when decomposing gives out a strong, cadaverous smell. They absorb oxygen and disengage carbonic acid, and by their avoidance of light they present a striking contrast to the rest of vegetation. Nevertheless, careful observation shows that they consist of parts, and
perform functions, by which they are allied to all other plants and closely related to one of the largest groups of the vegetal kingdom. They stand, in fact, at the head of the class of fungi, of which there are at least as many species as of all flowering plants put together.
These singular forms, though low in the scale when compared with the green and blossoming world around us, are yet complex and imposing when contrasted with the world of plant-life revealed by the microscope. They have a distinct vegetative system, and a highly-organized reproductive system. On examining the common cultivated mushroom, a species which grows wild in meadows and pastures, these separate systems may be readily distinguished. The vegetable mould or decaying substance on which it grows is penetrated with grayish-white delicate interlacing filaments which are represented by the root-like fibres shown in Fig. 1 . This webby mass constitutes the vegetative portion of the plant. It is called the mycelium, or, among dealers, the spawn, as by its means the plant is propagated in cultivation. In a dry state it may be kept dormant for a long time, and wall grow into a perfect plant under the influence of heat, moisture, and other favoring conditions.
From this mycelium arises the reproductive system—that portion of the mushroom which is seen above-ground and which may be compared to the inflorescence of higher plants. It consists of the long thick stem or stipe and the umbrella-like top, called the cap or pileus. On the lower surface of this cap vertical plates are seen radiating from the stem, though not connected with it. These plates are known as gills, and in a living specimen they will be found covered on all sides by a delicate membrane called the hymenium. Upon this hymenium are borne the reproductive bodies or spores, which are analogous to seeds.
To make our conception of the structure of this mushroom more complete, we will trace its growth from the beginning. The first visible portion is the mycelium, at certain points of which there appear, at an early stage, round tubercles not larger than a mustard-seed, which rapidly increase in size, push through the soil, and become more or less elongated, resembling the shaded cut in Fig. 2. There is yet no external sign of cap or gills, but a section of the tubercle will reveal a pair of dark-colored spots near the top (see 2 and 3, Fig. 2), which mark the position of the future gills. A little later the cap begins to take shape, the gills develop, and a membrane may be seen stretching from the stem to the edge of the growing cap. As maturity approaches, this membrane is ruptured and forms a ring around the stem, as shown in Fig. 8. This membrane is called the veil or
volva. The parts to be borne in mind, then, are the mycelium or vegetative portion, and the stem, cap, gills, hymenium, ring, and volva, all of which belong properly to the reproduction of the plant, and all, except the hymenium, may be readily traced in Fig. 3.
If, when the mushroom is mature, you cut off the stem close to the gills, and place the cap, gills downward, upon a sheet of paper for a few hours, or all night, it will leave behind a likeness of itself in the shape of radiating lines that correspond to the spaces between the pairs of gills. These lines are formed by minute microscopic spores that have been thrown down in profusion from the hymenium, and in greatest number from the opposed surfaces of the gills. In making the experiment with this mushroom use white paper, but for light-spored species black paper should be taken. These little germinal bodies are cellular in structure, and of the extremest minuteness; thousands of them are required to form a body the size of a pin's-head. Their color is constant, and is used as a means of identification; but among the higher plants color is a character that cannot be thus relied upon. The spore is a simple cell, and the entire mushroom is cellular in composition. The delicate threads of the mycelium are formed of rows of cells placed end to end, and microscopic inspection of thin slices from the stem and cap show, that they also are composed of cells alone.
The rank of this plant in the vegetal kingdom is settled by the direction of growth of its vegetative system and by the nature of its tissues. All flowering plants, as well as the ferns and mosses, have their vegetative part made up of root, stem, and leaves. The root grows downward and the stem upward. But the growth of the mycelium, the vegetative system of the mushroom, is horizontal; there are no signs of such organs as root and stem. In this respect it is on a level with lichens and sea-weeds, and belongs at the foot of the scale in vegetation. As respects the nature of its tissues and the absence of woody fibre in its composition, it resembles all the flowerless plants except ferns. But where are its immediate kindred? Have mushrooms no nearer relations than mosses, lichens, and sea-weeds?
To answer this question intelligently we must further observe the structure of fleshy fungi. In the common mushroom, as we have seen, the hymenium is spread out upon the lamellated structure of the gills—an arrangement, however, which is not general. It is peculiar to a single group known as agarics. This group has also the further general characteristic of preferring to grow in shady places. But in this latter respect the common mushroom is an exception. In its wild state it flourishes best in meadows and pastures. Its scientific name is composed of two words: one tells us the immediate group of toadstools to which it belongs, and the other expresses this exceptional feature in its constitution. The one which is put first is its family or surname, Agaricus; and the specific name, or what we may call the "given" name, is campestris (meaning field). These names are written in Latin for the convenience of the botanists of different nations speaking different tongues, but for whom the Latin is a common medium of communication.
Now, the structure of the under portion of the cap in some toad-stools is porous instead of lamellar. The surface of the spore-bearing hymenium is multiplied by means of pores or tubes which penetrate the substance of the cap, as seen in Fig. 4. Two stemless species of this sort are shown in the plate as growing upon an old tree.
Sometimes this under surface is seen to be quite smooth, or it may be simply wrinkled; sometimes it is warty or prickly, and in Fig. 5 it is represented as covered with spines. Again, in some species of fungi, the hymenium, instead of being situated externally, is inclosed in a membrane which bursts when its spores are ripe, and scatters them like a cloud of smoke to the winds. Of such is the puff-ball. Fig. 6, with which everybody is familiar.
|Fig. 5.—Hydnum Repandum.||Fig. 6.—Scleroderma Vulgare.|
These fleshy forms, however, although very numerous, constitute but a small part of this immense group. But most of the species included in it are either quite invisible, or else the parts which characterize them as fungi are so small as to be indistinguishable. The feature by which a fungus may always be known is the mycelium. Every plant of which this structure forms a part, spreading its web through-out the substance on, or in, which it grows, belongs among fungi. They differ among themselves in such comparatively unimportant respects as the mode of growth of the hymenium, or the degree of complexity of the reproductive system, but mycelia and spore production are their essential characters. In these diminutive organisms, the delicate mycelium is so minute as to traverse living plants and the pores of solid wood. The potato-rot is such a fungus—a sort of mould—the mycelium of which grows rapidly, penetrating the leaves, stem, and tubers, and causing quick decay. Dry-rot in timber is occasioned by the penetrating mycelium of fungi. The yeast and vinegar plants are submerged mycelia. The mildews, rusts, and smuts of grain—those scourges of the farmer—are all fungi. Their minute mycelium penetrates and destroys the tissues of plants, and, bursting through the cuticle, covers them with myriads of their orange, brown, and black spore. All those black, pustular growths seen on dead wood, bark, twigs, and leaves, and the whole tribe of moulds that cover every substance exposed to dampness, are fungi. Not only do these fungi ravage the living and the dead, but they fill the air with the countless myriads of their spores. These subtile particles, "invisible to the naked eye, and light almost as vapor, are continually floating in the air we breathe, or swimming in the water we drink, or lying amid the impalpable dust and sand of the soil, waiting the presence of warmth and moisture to burst into independent life. Myriads of the minute germs of moulds fasten upon various domestic articles, or dance about in the air-currents of our apartments, moving rapidly up and down and in every direction. The microscopist and the chemist have demonstrated the existence of these germs in greater or less quantity in the air of both country and town, out-of-doors as well as in-doors; and Prof. Tyndall by calling in the aid of optical analysis has, on this point, made assurance doubly sure. If we venture for a moment to imagine the overwhelming number of seeds which the different species of fungi must disseminate in the course of a single year—if we consider that each individual of the common puff-ball contains upward of ten million seeds, and these so small as to form a mere cloud when puffed into the air; and that a single filament of the mould which infests our bread and preserves will produce as many germs as an oak will acorns, so that a piece of decaying matter, not two inches square, will scatter upon the air, at the slightest breath of the summer breeze or the gentlest touch of an insect's wing, as many seeds, quick with life, as all the oaks of the country will produce acorns in a twelve-month—if we take these things into consideration, it is not too much to suppose that the seeds of fungi must be ubiquitous, and from their excessively minute size penetrate into every place, even into the stomachs and other parts of animals. Indeed, the difficulty seems to be to imagine a spot without them."
But, in looking up the relatives of the mushroom, we have been led too far away from the study of its structure. Recurring to the species with which we began our study, and a cluster of which, at different stages of growth, is represented in Fig. 3, let us inspect it once more, and make sure that we have a clear notion of all its parts. Observe the mycelium at the base, the stem, the unbroken volva in the young ones, the beginning of its rupture in a more advanced stage, and, finally, at the end of growth, the fully-developed cap, with its gills, and the ring left by the volva upon the stem. After this account of its structure, its specific description should be quite intelligible to anybody, and ought to suffice for the ready recognition of the living plant. It is as follows:
Cup fleshy, either smooth or scaly; its color is white, or tawny, or smoke-colored, or brown; gills free, when first formed pale, then changing to flesh-color, then to pink, next to purple, and, at length, tawny-black; stem white, full, firm, varying in shape, with a white persistent ring. Spores brown-black; volva quickly disappearing. In his recent work an "Fungi and their Uses," Coooke says of this plant that the color of the spores and gills, and the presence of the ring, are characters that never vary, but the color and scaliness of the cap, and other minor features, are variable; and, furthermore, he enjoins that it must not be sought in the woods. Its proper season is September and October.
There is another common, though much coarser species of edible mushroom, often mistaken for this one, and sold as such by dealers. Although it resembles the cultivated species, it may be easily distinguished by its big, ragged ring (Fig. 7), its pithy stem, tending to hollow, and its gills of a dirty-brownish white. It is also much larger,
being sometimes more than a foot across, while the common mushroom rarely exceeds three or lour inches; in good specimens its top is smooth and snowy white, and it turns of a brownish yellow as soon as broken. It is known as the snowball, or horse-mushroom (A. arvensis).
On the subject of distinguishing poisonous species, Mr, Cooke says that there is no golden rule which will enable us to tell at a glance the good species from the bad. The only safe guide lies in mastering, one by one, the specific distinctions, and increasing the knowledge through experience, as a child learns to distinguish a filbert from an acorn, or a leaf of sorrel from one of white-clover. The characters of half a dozen good, esculent species, he says, may be learned as easily as the ploughboy learns to discriminate as many species of birds. He tells us, moreover, that it is not enough to avoid poisonous species, but that discretion should be used in preparing and eating good ones. They change so rapidly, that even the cultivated mushroom, if long kept, is unfit for use. Nor is it enough that they be of good species and fresh; but plenty of salt must be used in their preparation, to neutralize any deleterious property, and pepper and vinegar are also recommended as advantageous.
Encouraged by these statements, from so distinguished and reliable an authority, we venture to present the pictures and descriptions of three more of the most highly esteemed of the edible fungi, which are common in the United States.
The Parasol Agaric.—Of this esteemed mushroom, Cooke remarks that it is in high request in Italy and France, and is also eaten in Austria, Germany, Spain, and England. It is easily identified. It has a fleshy cap, ovate when young, then bell-shaped, and afterward expanded and blunt-pointed. The extreme forms are shown in Fig. 8. The cuticle is more or less brown, and torn into patches or scales, except over the apex, these scales separating toward the margin. Flesh, white. Gills unconnected with the stem, and fixed to a collar on the cap around its top). Ring, persistent, loose on the stem. Stem six or eight inches high, tapering upward from a pear-like bulb at the base, hollow, with a loose pith, whitish brown, but more or less variegated with small and close-pressed scales.
Whenever a mushroom on a long stalk, enlarged at the base, presents a dry cuticle, more or less scaly, is darker colored over the blunt apex, has a movable ring and white gills, it must be the parasol agaric, and may be eaten without fear.—Robinson.
Chantarelle (Cantharellus cibarrius). Of this species Cooke says: “It has a most charming and enticing appearance and odor. It is almost universally eaten in all countries where it is found, England excepted.” Trattinnich says of it, “Not only this same fungus never did any one harm, but might even restore the dead.”
When young, its stem is white and solid, but becomes hollow and yellow. It is tapering, and passes into the substance of the cap, which is of the same color. The cap is lobed and irregular in shape (Fig. 9); its margin, at first curling inward, becomes expanded and wavy. The gills, or veins, as they are called, in this species, are thick, crooked, not compact, running some way down the stalk. Flesh white, fibrous, dense, with a fruity odor. Color, yellow, like yelk of eggs; deeper on the under surface. When raw, it has the pungent taste of pepper. Spores, of a pallid, ochre-color. It may be found from June to October.
Fairy-ring Champignon (Marasmius oreades). This delicious fungus (Fig. 10) grows in pastures in rings, or parts of rings, and may be known by the following characters: Cap smooth, fleshy, convex, rather blunt at apex, more or less compressed, tough, leathery, elastic, wrinkled; when water-soaked, brown; when dry, buff, or cream-color, the apex often remaining red-brown, as if scorched; gills free from the stem, distant, swelling out in the middle, the same color as the cap, but paler; stem equal, solid, twisted, very tough and fibrous, of a pale, silky-white color. This genus is much addicted, to dead leaves.—Cooke.
Another very acrid species (A. urens) has a similar appearance, but the gills are narrow and much crowded.
While all fungi are cellular in structure, they yet present a great variety of consistence. Some assume a corky or leathery firmness, while the substance of others is a mere watery pulp or gelatinous scum. Some are interlacing fibres, spread like a veil over decaying matters, while others are hard and tough like wood. They vary equally in taste and form. The cultivation of fungi for esculent purposes is confined to a single species, A. campestris, although, according to Cooke, there is no reason why others, for instance, Marasmius oreades, and the morel (see plate), should not succeed equally well. An unaccountable circumstance in this culture is the impossibility of growing mushrooms from spores. It is the mycelium or spawn which is always planted by gardeners, from which the production of mushrooms is simple enough, but how to obtain mycelium from spores is still a mystery. Other species present a similar difficulty, as the following statement from "Fungi and their Uses" will illustrate:
Mushroom-growing, as carried on in some parts of France, is so extraordinary as to deserve mention. In the vicinity of Paris there are extensive caves formed by stone-quarries long since abandoned. In these caves, sixty or seventy feet underground, and extending great distances, the temperature is equal and the air moist, and here mushroom-beds are made, and immense quantities of the plant are grown for home and foreign markets. An idea of the magnitude of the business may be formed when it is known that one proprietor has twenty-one miles of beds, another sixteen, another seven, and so on through a long list. In the ramifications of the cave of Montrouge (Fig. 11), just outside the fortifications of Paris, there are six or seven miles' run of mushroom-beds. It is entered through a circular opening, like the mouth of a well, and the only mode of descent is down a shaky pole, furnished with cross-bars, the base of which rests in darkness sixty feet below.
A gentleman who visited this cave remarks:
Of the way mushrooms are usually cultivated, and the various modes of cooking them, it is not our purpose to speak. Whoever
wishes to study these subjects will find them fully treated in Robinson's "Mushroom Culture." To give an idea of the rich stores of mushrooms in this country, we quote from a communication of the late Dr. Curtis, of South Carolina, in reply to inquiries of Rev. C. Berkeley:
Among our best and standard mushrooms, Dr. Curtis mentions the meadow, the horse, and umbrella mushrooms, but adds:
Dr. Curtis says, however, that the same species varies very much in flavor in different regions, owing probably to differences of soil, exposure, shade, moisture, or temperature. He has found perfectly sound pink-gills with unpleasant odor and taste, and horse-mushrooms that were "perfectly detestable." But, whether such exceptional specimens are poisonous or not, he thinks of no consequence, because no human being could be induced to swallow them.
- Names of Species shown in the Plate: 1. Fly-blown mushroom—Agaricus muscarius. 2. Common mushroom—Agaricus campestris. 3. Round-headed morel—Morchella esctclenta. 4. Small-headed morel—Morchella hyhrida. 5. Tall cylindrical agaric—Agaricus comatus. 6. Variable wood agaric—Agaricus gilvus. 7. Shaggy agaric—Agaricus Jloccosus. 8. Spangled watery agaric—Agaricus micaceous. 9. Warty false puff-ball—Scleroderma verrucosum. 10. Large bladder-like peziza—Peziza vasculosa. 11. Alpine amanita—Amanita nivalis. 12. Red-stemmed boletus—Boletus luridus. 13. Scaly hydruim—Hydruim imhricatum. 14. Hairy earth-tongue—Geofelossum hirsutum. 15. Hispid polyporus—Folyporus hispidtis. 16. Sulphur-colored polyporus—Polyporus sulphureus. 17. Carmine peziza—Peziza coccinea. 18. Scaly hydruim—Hydruim imbricatum. 19. Pale-crested agaric—Agaricus cristatus. 20. Mitral helvela—Ildvela mitra. 21. Tuberous agaric—Agaricus tuberosum. 22. False puflf-ball—Scleroderma cepa. 23. Large-stemmed peziza—Peziza macropus. 24. Green and yellow agaric—Agaricus psittacinus. 25. Crisped helvella—Helvella leucophcea. 26. Reticulated peziza—Peziza reticulata. 27. Yellow spatliulavia—Spathularia favida.