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MUSHROOM

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Originally appearing in Volume V19, Page 72 of the 1911 Encyclopedia Britannica.
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MUSHROOM .' There are few more useful, more easily recognized, or more delicious members of the See also:

vegetable See also:kingdom than the See also:common mushroom, known botanically as Agaricus campestris (or Psalliota campestris). It grows in See also:short grass in the temperate regions of all parts of the See also:world. Many edible See also:fungi depend upon See also:minute and often obscure botanical characters for their determination, and may readily be See also:con-founded with worthless or poisonous See also:species; but that is not the See also:case with the common mushroom, for, although several other species of Agaricus somewhat closely approach it in See also:form and See also:colour, yet the true mushroom, if See also:sound and freshly gathered, may be distinguished from all other fungi with See also:great ease. It almost invariably grows in See also:rich, open, breezy pastures, in places where the grass is kept short by the grazing of horses, herds and flocks. Although this plant is popularly termed the " meadow See also:mush-See also:room," it never as a See also:rule grows in meadows. It never grows in wet boggy places, never in' See also:woods, or on or about stumps of trees. An exceptional specimen or an uncommon variety may sometimes be seen in the above-mentioned abnormal places, but the best, the true, and common variety of the table is the produce of short, upland, See also:wind-swept pastures. A true mushroom is never large in See also:size; its cap very seldom exceeds 4, at most 5 in. in See also:diameter. The large examples measuring from 6 to 9 or more in. across the cap belong to Agaricus arvensis, called from its large size and coarse texture the See also:horse mushroom, which grows in meadows and See also:damp shady places, and though generally wholesome is coarse and sometimes indigestible. The mushroom usually grown in gardens or hot-beds, in cellars, sheds, &c., is a distinct variety known as Agaricus hortensis. On being cut or broken the flesh of a true mushroom remains See also:white or nearly so, the flesh of the coarser horse mushroom changes to See also:buff or sometimes to dark See also:brown. To summarize the characters of a true mushroom —it grows only in pastures; it is of small size, dry, and with unchangeable flesh; the cap has a frill; the gills are See also:free from the See also:stem, the spores brown-See also:black or deep See also:purple-black in colour, and the stem solid or slightly pithy.

When all these characters are taken together no other mushroom-like fungus—and nearly a thousand species grow in See also:

Britain—can be con-founded with it. The parts of a mushroom consist chiefly of stem and cap; the stem has a clothy See also:ring See also:round its See also:middle, and the cap is furnished underneath with numerous radiating coloured gills. Fig. r (r) represents a See also:section through an See also:infant mushroom, (2) a mature example, and (3) a See also:longitudinal section through a fully See also:developed mushroom. The cap n, E is fleshy, See also:firm and white within, never thin and watery; externally it is See also:pale brown, dry, often slightly silky or floccose, never viscid. The cuticle of a mushroom readily peels away from the flesh beneath, as shown at F. The cap has a narrow dependent margin or frill, as shown at G, and in section at Ii; this dependent frill originates in the rupture of a delicate continuous wrapper, which in the See also:infancy of the mushroom entirely wraps the See also:young plant; it is shown in its continuous See also:state at J, and at the moment of rupture at K. The gills underneath the cap r,, M, N are at first white, then See also:rose-coloured, at length brown-black. A point of great importance is to be noted in the See also:attachment of the gills near the stem at o, P; the gills in the true mushroom are (as shown) usually more or less free from the stem, they never grow boldly against it or run down it; they may sometimes just See also:touch the spot where the stem joins the bottom of the cap, but never more; there is usually a slight channel, as at h, all round the See also:top of the stem. When a mushroom is perfectly ripe and the gills are brown-black in colour, they throw down a thick dusty See also:deposit of See also:fine brown-black or purple-black spores; it is essential to See also:note the colour. The spores on germination make a white felted See also:mat, more or less dense, of mycelium; this, when compacted with dry, See also:half-decomposed dung-, is the mushroom spawn of gardeners. The stem is firm, slightly pithy up the middle, but never hollow; it bears a floccose ring near its middle, as illustrated at Q, Q; this ring originates by the rupture of the thin See also:general wrapper is of the infant plant. Like all widely spread and much-cultivated See also:plants, the edible ' The earlier 15th-See also:century form of the word was musseroun, muscheron, &c., and was adapted from the See also:French mousseron, which is generally connected with See also:mouse, See also:moss.mushroom has numerous varieties, and it differs in different places and under different modes of culture in much the same way as our See also:kitchen-See also:garden plants differ from the type they have been derived from, and from each other.

In some instances these See also:

differences are so marked that they have led some botanists to regard as distinct species many forms usually esteemed by others as varieties only. A small variety of the common mushroom found in pastures has been named A. Pratensis; it differs from the type in having a pale reddish-brown scaly top, and the flesh on being cut or broken changes to pale rose-colour. A variety still more' marked, with a darker brown cap and the flesh changing to a deeper rose, and sometimes See also:blood-red, has been described as A. rufescens. The well-known compact variety of mushroom-growers, with its white cap and dull purplish See also:clay-coloured gills, is A. hortentis. Two sub-varieties of this have been described under the names of A. See also:Buchanan- and A. elongatus, and other distinct forms are known to botanists. A variety also grows in woods named A. silvicola; this can only be distinguished from the pasture mushroom by its elongated bulbous stem and its externally smooth cap. There is also a fungus well known to botanists and cultivators which appears to be inter-mediate between the pasture variety and the See also:wood variety, named A. vaporarius. The large See also:rank horse mushroom, now generally referred to as A. arvensis, is probably a variety of the pasture mush-room; it grows in rings in woody places and under trees and hedges in meadows; it has a large scaly round cap, and the flesh quickly changes to buff or brown when cut or broken; the stem too is hollow. An unusually scaly form of this has been described as A. villaticus and another as A. See also:augustus. A species, described by See also:Berkeley and See also:Broome as distinct from both the pasture mushroom and horse mushroom, has been published under the name of A. elvensis.

This grows under oaks, in clusters—a most unusual See also:

character for the mushroom, and is said to be excellent for the table. An allied fungus See also:peculiar to woods, with a less fleshy cap than the true mushroom, with hollow stem, and strong odour, has been described as a See also:close ally of the pasture mushroom under the name of A. silvaticus; its qualities for the table have not been recorded. Many instances are on See also:record of symptoms of poisoning, and even See also:death, having followed the See also:consumption of plants which have passed as true mushrooms; these cases have probably arisen from the examples consumed being in a state of decay, or from some See also:mistake as to the species eaten. It should always be specially noted whether the fungi to be consumed are in a fresh and wholesome See also:condition, otherwise they See also:act as a See also:poison in precisely the same way as does any other semi-putrid vegetable. Many instances are on record where mushroom-beds have been invaded by a growth of See also:strange fungi and the true mushrooms have been ousted to the See also:advantage of the new-corners. When mushrooms are gathered for See also:sale by persons unacquainted with the different species mistakes are of frequent occurrence. A very common See also:spurious mushroom in markets is A. velutinus, a slender, ringless, hollow-stemmed, black-gilled fungus, common in gardens and about dung and stumps; it is about the size of a mushroom, but thinner in all its parts and far more brittle; it has a black hairy fringe See also:hanging round the edge of the cap when fresh. Another spurious mushroom, and equally common in dealers' baskets, is A. lacrymabundus; this grows in the same positions as the last, and is somewhat fleshier and more like a true mush-room; it has a hollow stem and a slight ring, the gills are black-brown mottled and generally studded with See also:tear-like drops of moisture. In both these species the gills distinctly touch and grow on to the stem. Besides these there are numerous other black-gilled species which find a See also:place in baskets—some species far too small to See also:bear any resemblance to a mushroom, others large and deliquescent, generally belonging to the stump- and dung-See also:borne genus Coprinus. The true mushroom itself is to a great extent a dung-borne species, therefore mushroom-beds are always liable to an invasion from other dung-borne forms. The spores of all fungi are constantly floating about in the See also:air, and when the spores of dung-infesting species alight on a mushroom-See also:bed they find a nidus already prepared that exactly suits them; and if the spawn of the new-corner becomes more profuse than that of the mushroom the stranger takes up his position at the expense of the mushroom.

There is also a fungus named Xylaria vaporaria, which sometimes fixes itself on mushroom-beds and produces such an enormous quantity of See also:

string-like spawn that the entire destruction of the bed results. This spawn is some-times so profuse that it is pulled out of the beds in enormous masses and carted away in barrows. Sometimes cases of poisoning follow the consumption of what have really appeared to gardeners to be true bed-mushrooms, and to See also:country folks as small horse mushrooms. The case is made more complicated by the fact that these highly poisonous forms now and then appear upon mushroom-beds to the exclusion of the mush-rooms. This dangerous counterfeit is A. fastibilis, or sometimes A. crustuliniformis, a close ally if not indeed a See also:mere variety of the first. A description of one will do for both, A. fastibilis being a little the more slender of the two. Both have fleshy caps, whitish, moist and clammy to the touch; instead of a pleasant odour, they have a disagreeable one; the stems are ringless, or nearly so; and the gills, which are palish-clay-brown, distinctly touch and grow on to the solid or pithy stem. These two fungi usually grow in woods, but sometimes in hedges and in shady places in meadows, or even, as has been said, as invaders on mushroom-beds. The pale clay-coloured gills, offensive odour, and clammy or even viscid top are decisive characters. A reference to the accompanying See also:illustration (fig. 2), which is about one-half natural size, will give a See also:good See also:idea of A. fastibilis; the difference in the nature of the attachment of the gills near the stem is seen at R, the See also:absence of a true ring at s, and of a pendent frill at T. The colour, with the exception of the gills, is not unlike that of the mushroom.

In determining fungi no single character must be relied upon as conclusive, but all the characters must be taken together. Sometimes a beautiful, somewhat slender, fungus peculiar to stumps in woods is mistaken for the mushroom in A. cervinus; it has a tall, solid, white, ringless stem and somewhat thin brown cap, furnished underneath with beautiful rose-coloured gills, which are free from the stun as in the mushroom, and which Fin. 2.-Poisonous Mushroom (Agaricus fastibilis). never turn black. It is probably a poisonous plant, belonging, as it does, to a dangerous See also:

cohort. Many other species of Agaricus more or less resemble A. campestris, notably some of the plants found under the sub-genera Lepiota, Volvaria, Pholiota and Psalliota; but when the characters are noted they may all with a little care be easily distinguished from each other. The better See also:plan is to discard at once all fungi which have not been gathered from open pastures; by this act alone more than nine-tenths of worthless and poisonous species will be excluded. In cases of poisoning by mushrooms immediate medical See also:advice should be secured. The dangerous principle is a narcotic, and the symptoms are usually great See also:nausea, drowsiness, stupor and pains in the See also:joints. A good palliative is sweet oil; this will allay any corrosive irritation of the See also:throat and See also:stomach, and at the same See also:time cause vomiting. See also:Paris mushrooms are cultivated in enormous quantities in dark underground cellars at a See also:depth of from 6o to 16o ft. from the See also:surface. The See also:stable manure is taken into the tortuous passages of these cellars, and the spawn introduced from masses of dry dung where it occurs naturally.

In See also:

France mushroom-growers do not use the compact blocks or bricks of spawn so See also:familiar in See also:England, but much smaller flakes or " leaves " of dry dung in which the spawn or mycelium can be seen to exist. Less manure is used in these cellars than we generally see in the mushroom-houses of England, and the surface of each bed is covered with about an See also:inch of fine white stony See also:soil. The beds are kept artificially moist by the application of See also:water brought from the surface, and the different galleries bear crops in See also:succession. As one is exhausted another is in full bearing, so thatby a systematic arrangement a single proprietor will send to the surface from 300 lb to 3000 lb of mushrooms per See also:day. The passages sometimes extend over several See also:miles, the beds sometimes occupying over 20 m., and, as there are many proprietors of cellars, the produce of mushrooms is so large that not only is Paris fully supplied, but vast quantities are forwarded to the different large towns of See also:Europe; the mushrooms are not allowed to reach the fully See also:expanded condition, but are gathered in a large See also:button state, the whole growth of the mushroom being removed and the hole See also:left in the manure covered with fine See also:earth. The beds remain in bearing for six or eight months, and then the spent manure is taken to the surface again for garden and See also:field purposes. The equable temperature of these cellars and their freedom from See also:draught is one cause of their great success; to this must be added the natural virgin spawn, for by continually using spawn taken from mushroom-producing beds the potency for See also:reproduction is weakened. The beds produce mushrooms in about six See also:weeks after this spawning. The common mushroom (Agaricus campestris) is propagated by spores, the fine black dust seen to be thrown off when a mature specimen is laid on white See also:paper or a white dish; these give rise to what is known as the " spawn " or mycelium, which consists of whitish threads permeating dried dung or similar substances, and which, when planted in a proper See also:medium, runs through the See also:mass, and eventually develops the fructification known as the mushroom. This spawn may be obtained from old pastures, or decayed mushroom beds, and is See also:purchased from nurserymen in the form of bricks charged with the mycelium, and technically known as mushroom spawn. When once obtained, it may be indefinitely preserved. It may be produced by placing quantities of horse-dung saturated with the urine of horses, especially of See also:stud horses, with alternate layers of rich earth, and covering the whole with See also:straw, to exclude See also:rain and air; the spawn commonly appears in the heap in about two months afterwards.

The droppings of See also:

stall-fed horses, or of such as have been kept on dry See also:food, should be made use of. The old method of growing mushrooms in ridges out of doors, or on prepared beds either level or sloping from a back See also:wall in sheds or cellars, may generally be adopted with success. The beds are formed of horse-droppings which have been slightly fermented and frequently turned, and may be made 2 or 3 ft. broad and of any length. A layer of dung about 8 or io in. thick is first deposited, and covered with a See also:light dryish earth to the depth of 2 in.; and two similar layers with similar coverings are added, the whole being made narrower as it advances in height. When the bed is finished, it is covered with straw to protect it from rain, and also from parching influences. In about ten days, when the mass is milkwarm, the bed will be ready for spawning, which consists of inserting small pieces of spawn bricks into the sloping sides of the bed, about 6 in. asunder. A layer of fine earth is then placed over the whole, and well beaten down, and the surface is covered with a thick coat of straw. When the See also:weather is temperate, mushrooms will appear in about a See also:month after the bed has been made, but at other times a much longer See also:period may elapse. The See also:principal things to be attended to are to preserve a moderate state of moisture and a proper mild degree of warmth; and the treatment must vary according to the See also:season. These See also:ordinary See also:ridge beds furnish a good See also:supply towards the end of summer, and in autumn. To command a See also:regular supply, how-ever, at all seasons, the use of a mushroom-See also:house will be found very convenient. The material employed in all cases is the droppings of horses, which should be collected fresh, and spread out in thin layers in a dry place, a portion of the short See also:litter being retained well moistened by horse-urine.

It should then be thrown together in ridges and frequently turned, so as to be kept in an incipient state of See also:

fermentation, a little dryish friable See also:loam being mixed with it to retain the See also:ammonia given off by the dung. With this or a mixture of horse-dung, loam, old mushroom-bed dung, and half-decayed leaves, the beds are built up in successive layers of about 3 in. thick, each layer being beaten firm, until the bed is 9 or io in. thick. If the See also:heat exceeds 8o°, holes should be made to moderate the fermentation. The beds are to be spawned when the heat moderates, and the surface is then covered with a sprinkling of warmed loam, which after a few days is made up to a thickness of 2 in., and well beaten down. The beds made partly of old mushroom-bed dung often contain sufficient spawn to yield a See also:crop, without the introduction of See also:brick or cake spawn, but it is advisable to spawn them in the regular way. The spawn should be introduced an inch or two below; the surface when the heat has declined to about 750, indeed the bed ought never to exceed 8o°. The surface is to be afterwards covered with I.-ay or litter. The atmospheric temperature should range from 6o° to 65° till the mushrooms appear, when it may drop a few degrees, but not See also:lower than 55°. If the beds require watering, water of about 8o° should be used, and it is preferable to moisten the covering of litter rather than the surface of the beds themselves. Jt is also beneficial, especially in the case of partially exhausted beds, to water with a dilute See also:solution of See also:nitre. For a See also:winter supply the beds should be made towards the end of See also:August, and the end of See also:October. Slugs and woodlice are the worst enemies of mushroom crops.

The See also:

Fairy-ring Champignon.—This fungus, Marasmius Oreades, is more universally used in France and See also:Italy than in England, although it is well known and frequently used both in a fresh and in a dry state in England. It is totally different in See also:appearance from the pasture mushroom, and, like it, its characters are so distinct that there is hardly a possibility of making a mistake when its peculiarities are once comprehended. It has more than one advantage over the meadow mushroom in its extreme commonness, its profuse growth, the length of the season in which it may be gathered, the See also:total absence of varietal forms, its adaptability for being dried and preserved for years, and its persistent delicious See also:taste. It is by many esteemed as the best of all the edible fungi found in Great Britain. Like the mushroom, it grows in short open pastures and amongst the short grass of open roadsides; sometimes it appears on lawns, but it never occurs in woods or in damp shady places. Its natural See also:habit is to grow in rings, and the grassy fairy-rings so frequent amongst the short grass of See also:downs and pastures in the See also:spring are generally caused by the nitrogenous manure applied to the soil in the previous autumn by the decay of a circle of these fungi. Many other fungi in addition to the fairy-ring champignon grow in circles, so that this habit must merely be taken with its other characters in cases of doubt. A glance at the illustration (fig. 3) will show how entirely the fairy-ring champignon differs from the mushroom. In the first place, it ;r Frc. 3.-The Fairy-ring Champignon (Marasmius oreades). is about one-half the size of a mushroom, and whitish-buff in every See also:part, the gills always retaining this colour and never becoming See also:salmon-coloured, brown or black.

The stem is solid and corky, much more solid than the flesh of the cap, and perfectly smooth, never being furnished with the slightest trace of a ring. The buff-gills are far apart (v), and in this they greatly differ from the some-what crowded gills of the mushroom; the junction of the gills with the stem (w) also differs in character from the similar junction in the mushroom. The mushroom is a semi-deliquescent fungus which rapidly falls into putridity in decay, whilst the champignon dries up into a leathery substance in the See also:

sun, but speedily revives and takes its See also:original form again after the first shower. To this character the fungus owes its generic name (Marasmius) as well as one of its most valuable qualities for the table, for examples may be gathered from See also:June to See also:November, and if carefully dried may be hung on strings for culinary purposes and preserved without deterioration for several years; indeed, many persons assert that the rich flavour of these fungi increases with years. Champignons are highly esteemed (and especially is this the case abroad) for adding a most delicious flavour to stews, soups and gravies. A fungus whkh may carelessly be mistaken for the mushroom is M. peronatus, but this grows in woods amongst dead leaves, and has a hairy See also:base to the stem and a somewhat acrid taste. Another is M. wrens; this also generally grows in woods, but the gills are not nearly so deep, they soon become brownish, the stem is downy, and the taste is acrid. An Agaricus named A. dryophilus has sometimes been gathered in mistake for the champignon, but this too grows in woods where the champignon never grows; it has a hollow instead of a solid stem, gills crowded together instead of far apart, and flesh very See also:tender and brittle instead of tough. A small esculent ally of the champignon, named M. scovodonius, is sometimes found in pastures in Great Britain; this is largely consumed on the See also:Continent, where it is esteemed for its powerful flavour of See also:garlic. In England, where garlic is not used to a large extent, this fungus is not sought for. Another small and common species, M. porreus, is pervaded with a garlic flavour to an equal extent with the last. A third species, M. alliaceus, is also strongly impregnated with the See also:scent and taste of onions or garlic.

Two species, M. impudicus and M. _foetidus, are in all stages of growth highly foetid. The curious little edible Agaricus esculentus, although placed under the sub-genus Collybia, is allied by its structure to Marasmius. It is a small See also:

bitter species common in upland pastures and See also:fir plantations See also:early in the season. Although not gathered for the table in England, it is greatly prized in some parts of the Continent.

End of Article: MUSHROOM

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