Chapter 22

USES OF MUSHROOMS.[C]

The most prominent and at present important use of mushrooms from the standpoint of the utilitarian is as an article of food. We have now learned that their food value as a nutrient substance is not so great as has been fondly supposed, but, as Mr. Clark points out in Chapter XXII, in addition to the value they certainly do possess as food, they have very great value as condiments or food accessories, and "their value as such is beyond the computation of the chemist or physiologist. They are among the most appetizing of table delicacies, and add greatly to the palatability of many foods when cooked with them." Mushrooms undoubtedly possess a food value beyond that attributed to them by the chemist or physiologist, since it is not possible in laboratory analysis to duplicate the conditions which exist in the natural digestion and assimilation of foods.

Probably the larger number of persons, in America, at present interested in mushrooms, are chiefly concerned with them as an article of food, but a great many of these persons love to tramp to the fields and woods in quest of them just as the sportsman loves to hunt his game with dog and gun. It is quite likely that there will always be a large body of persons who will maintain a lively interest in the collection of _game_ mushrooms for food. There are several reasons for this. The zest of the search, the pleasure of discovery, and the healthfulness of the outdoor recreation lend an appetizing flavor to the fruits of the chase not to be obtained by purchasing a few pounds of cultivated mushrooms on the market. It cultivates powers of observation, and arouses a sympathetic feeling toward nature, and with those outdoor environments of man which lend themselves so happily in bettering and brightening life, as well as in prolonging it.

Many others are discovering that the observation of form and habits of mushrooms is a very interesting occupation for those who have short periods of time at their disposal weekly. It requires but a little observation to convince one that there is an interesting variety of form among these plants, that their growth and expansion operate in conformity with certain laws which result in great variation in form and habit of the numerous kinds on the ground, on leaves, on branches, on tree trunks, etc.

Another very favorable indication accompanying the increasing interest in the study of these plants, is the recognition of their importance as objects for nature study. There are many useful as well as interesting lessons taught by mushrooms to those who stop to read their stories. The long growth period of the spawn in the ground, or in the tree trunk, where it may sometimes be imprisoned for years, sometimes a century, or more, before the mushroom appears, is calculated to dispel the popular notion that the mushroom "grows in a night." Then from the button stage to the ripe fruit, several days, a week, a month, or a year may be needed, according to the kind, while some fruiting forms are known to live from several to eighty or more years. The adjustment of the fruit cap to a position most suitable for the scattering of the spores, the different ways in which the fruit cap opens and expands, the different forms of the fruit surface, their colors and other peculiarities, suggest topics for instructive study and observation. The inclination, just now becoming apparent, to extend nature study topics to include mushrooms is an evidence of a broader and more sympathetic attitude toward nature.

A little extension of one's observation on the habits of these plants in the woods will reveal the fact that certain ones are serious enemies of timber trees and timber. It is quite easy in many cases for one possessing no technical knowledge of the subject to read the story of these "wood destroying" fungi in the living tree. Branches broken by snow, by wind, or by falling timber provide entrance areas where the spores, lodging on the heart wood of broken timber, or on a bruise on the side of the trunk which has broken through the living part of the tree lying just beneath the bark, provide a point for entrance. The living substance (_protoplasm_) in the spawn exudes a "juice" (_enzyme_) which dissolves an opening in the wood cells and permits the spawn to enter the heart of the tree, where decay rapidly proceeds as a result. But very few of these plants can enter the tree when the living part underneath the bark is unbroken.

These observations suggest useful topics for thought. They suggest practical methods of prevention, careful forestry treatment and careful lumbering to protect the young growth when timber trees are felled. They suggest careful pruning of fruit and shade trees, by cutting limbs smooth and close to the trunk, and then painting the smooth surface with some lead paint.

While we are thus apt to regard many of the mushrooms as enemies of the forest, they are, at the same time, of incalculable use to the forest. The mushrooms are nature's most active agents in the disposal of the forest's waste material. Forests that have developed without the guidance of man have been absolutely dependent upon them for their continued existence. Where the species of mushrooms are comparatively few which attack living trees, there are hundreds of kinds ready to strike into fallen timber. There is a degree of moisture present on the forest floor exactly suited to the rapid growth of the mycelium of numbers of species in the bark, sap wood, and heart wood of the fallen trees or shrubs. In a few years the branches begin to crumble because of the disorganizing effect of the mycelium in the wood. Other species adapted to growing in rotting wood follow and bring about, in a few years, the complete disintegration of the wood. It gradually passes into the soil of the forest floor, and is made available food for the living trees. How often one notices that seedling trees and shrubs start more abundantly on rotting logs.

The fallen leaves, too, are seized upon by the mycelium of a great variety of mushrooms. It is through the action of the mycelium of mushrooms of every kind that the fallen forest leaves, as well as the trunks and branches, are converted into food for the living trees. The fungi, are, therefore, one of the most important agents in providing available food for the virgin forest.

The spawn of some fungi in the forest goes so far, in a number of cases, as to completely envelop those portions of the roots of certain trees as to prevent the possibility of the roots taking up food material and moisture on their own account. In such cases, the oaks, beeches, hornbeams, and the like, have the younger parts of their roots completely enveloped with a dense coat of mycelium. The mycelium in these cases absorbs the moisture from the soil or forest floor and conveys it over to the roots of the tree, and in this way supplies them with both food and water from the decaying humus, the oak being thus dependent on the mycelium. In the fields, however, where there is not the abundance of humus and decaying leaves present in the forest, the coating of mycelium on the roots of these trees is absent, and in this latter case the young roots are provided with root hairs which take up the moisture and food substances from the soil in the ordinary way.

The mushrooms also prevent the forest from becoming choked or strangled by its own fallen members. Were it not for the action of the mushroom mycelium in causing the decay of fallen timber in the forest, in time it would be piled so high as to allow only a miserable existence to a few choked individuals. The action of the mushrooms in thus disposing of the fallen timber in the forests, and in converting dead trees and fallen leaves into available food for the living ones, is probably the most important role in the existence of these plants. Mushrooms, then, are to be given very high rank among the natural agencies which have contributed to the good of the world. When we contemplate the vast areas of forest in the world we can gain some idea of the stupendous work performed by the mushrooms in "house cleaning," and in "preparing food," work in which they are still engaged.

FUNGI IN THE ARTS.

A number of different species of mushrooms have been employed in the manufacture of useful articles. Their use for such purposes, however, was more common in the past than at present, and it is largely therefore a matter of interest at the present time, though some are still employed for purposes of this kind.

=Tinder mushroom, or amadou.=--The _Polyporus fomentarius_, or "tinder mushroom" or, as it is sometimes called, "German tinder," was once employed in the manufacture of tinder. The outer hard coat was removed and the central portion, consisting almost entirely of the tube system of several years' growth, was cut into strips and beaten to a soft condition. In this form it was used as tinder for striking fire.

The inner portion was also used in making caps, chest-protectors, and similar articles. A process now in vogue in some parts of Germany, is to steam the fruit bodies, remove the outer crust, and then, by machinery constructed for the purpose, shave the fruit body into a long, thin strip by revolving it against a knife in much the same way that certain woods are shaved into thin strips for the manufacture of baskets, plates, etc. Some articles of clothing made from this fungus material are worn by peasants in certain parts of Europe.

=Mushrooms for razor strops.=--The beech polyporus (_P. betulinus_) several centuries ago was used for razor strops. The fruit body after being dried was cut into strips, glued upon a stretcher, and smoothed down with pumice stone (Asa Gray Bull. 7: 18, 1900). The sheets of the weeping merulius (see Fig. 189) were also employed for the same purpose, as were also the sheets of "punk" formed from mycelium filling in cracks in old logs or between boards in lumber piles. Sometimes extensive sheets of this punk are found several feet long and a foot or more wide. These sheets of pure mycelium resemble soft chamois skin or soiled kid leather.

=Mushrooms employed for flower pots.=--In Bohemia (according to Cooke, Fungi, etc., p. 103) hoof-shaped fruit bodies of _Polyporus fomentarius_ and _igniarius_ are used for flower pots. The inner, or tube portion, is cut out. The hoof-shaped portion, then inverted and fastened to the side of a building or place of support, serves as a receptacle for soil in which plants are grown.

=Curios.=--The _Polyporus applanatus_ is much sought by some persons as a "curio," and also for the purpose of etching. In the latter case they serve as pastels for a variety of art purposes. The under surface of the plant is white. All collectors of this plant know that to preserve the white fruiting surface in a perfect condition it must be handled very carefully. A touch or bruise, or contact with other objects mars the surface, since a bruise or a scratch results in a rapid change in color of the injured surface. Beautiful etchings can thus be made with a fine pointed instrument, the lines of color appearing as the instrument is drawn over the surface.

=Fungi for medicinal purposes.=--A number of the fungi were formerly employed in medicine for various purposes, but most of them have been discarded. Some of the plants were once used as a purgative, as in the case of the officinal polyporus, the great puff ball, etc. The internal portion of the great puff ball has been used as an anodyne, and "formidable surgical operations have been performed under its influence." It is frequently used as a narcotic. Some species are employed as drugs by the Chinese. The anthelmintic polyporus is employed in Burmah as a vermifuge. The ergot of rye is still employed to some extent in medicine, and the ripe puff balls are still used in some cases to stop bleeding of wounds.

=Luminosity of fungi.=--While the luminosity possessed by certain fungi cannot be said to be of distinct utility, their phosphorescence is a noteworthy phenomenon. That decaying wood often emits this phosphorescent light has been widely observed, especially in wooded districts. It is due to the presence of the mycelium of one of the wood destroying fungi. The luminosity is often so bright that when brought near a printed page in the dark, words can be read. Hawthorne "reported the light from an improvised torch of mycelium infected wood, to have carried him safely several miles through an otherwise impassable forest." (Asa Gray, Bull. =7=: 7, 1900). The sulphur polyporus is said sometimes to be phosphorescent. The _Clitocybe illudens_ (see Fig. 92) has long been known to emit a strong phosphorescent light, and has been called "Jack-my-lantern." This plant often occurs in great abundance. At mountain hotels it is often brought in by day, and the guests at night, discovering its luminosity, trace grotesque figures, or monograms, on the ground by broken portions, which can be seen at a considerable distance. _Lentinus stipticus_ in this country is also phosphorescent. In Europe, the _Pleurotus olearius_ (very closely related to our _Clitocybe illudens_) on dead olive trunks is one of the best known of the phosphorescent species. Other phosphorescent species are, according to Tulasne, _A. igneus_ from Amboyna, _A. noctileucus_ in Manila, and _A. gardneri_ in Brazil.

The use of certain mushrooms in making intoxicant beverages is referred to in Chapter XXII.

Since the artificial cultivation of mushrooms for food is becoming quite an industry in this country with some, the following chapter is devoted to a treatment of the subject. Mention may be made here, however, of the attempts in parts of France to cultivate truffles, species of subterranean fungi belonging to the ascomycetes (various species of the genus _Tuber_). It had long been observed that truffles grow in regions forested by certain trees, as the oak, beech, hornbeam, etc. Efforts were made to increase the production of truffles by planting certain regions to these trees. Especially in certain calcareous districts of France (see Cooke, Fungi, etc., p. 260) young plantations of oak, beech, or beech and fir, after the lapse of a few years, produced truffles. The spores of the truffles are in the soil, and the mycelium seems to maintain some symbiotic relation with the roots of the young trees, which results in the increase in the production of the fruit bodies. Dogs and pigs are employed in the collection of truffles from the ground.

Comparatively few of the truffles, or other subterranean fungi, have been found in America, owing probably to their subterranean habit, where they are not readily observed, and to the necessity of special search to find them. In California, however, Dr. Harkness (Proc. Calif. Acad. Sci.) has collected a large number of species and genera. Recently (Shear. Asa Gray Bull. 7: 118, 1899) reports finding a "truffle" (_Terfezia oligosperma_ Tul.) in Maryland, and _T. leonis_ occurs in Louisiana.

FOOTNOTES:

[C] There is not room here to discuss the uses of other fungi than the "mushrooms."