# The Encyclopedia Americana (1906)/Mushroom

See also the 1906 Encyclopedia Americana disclaimer.
Mush'room, a popular term loosely applied to many species of higher fungi, especially such as have a cap (pileus) upon an erect stalk. Primarily, the mushroom is Agaricus campestris (see Fungi), the only species cultivated upon a commercial scale. Though more than 700 species of mushrooms have been proved edible within the last half century, and though many others will doubtless be proved harmless, the novice should be cautious in trying new species. Each unfamiliar kind should be subjected to rigid examination first by smell, and malodorous ones discarded; then by taste, a small piece being nibbled but not swallowed. If no ill results follow in the course of several hours, a small piece may be swallowed. If no evil effects follow, but the flavor raw is unpleasant, cooked morsels may be cautiously tried, and results noted. Each individual must decide what species agree with him, because some systems will not endure kinds innocuous to others. Nervous fear of fancied bad symptoms must be con- trolled, or real illness may be induced by the imagination.
Several species are popularly reputed viru- lent which do not produce any marked effect upon the health for several hours, and which are widely feared as deadly. Since the two com- monest of these (Amanita muscaria and A. phalloides) are often mistaken for the common mushroom, the novice should never gather any toadstools in the woods under the impression that they are the proper mushroom, which grows in pastures, lawns, etc., and not in shady places. Further, all species with yellow or white gills should be avoided until known to be edible. The common mushroom has pink gills when young, and purplish-brown or black gills when mature.
Several of the thousand species of the genus Agaricus are valued for food, but the common mushroom (A. campestris) is the most important. It is occasionally found in open and grassy glades; never in the deep forest, but most frequently in old pastures and lawns, especially in autumn, but often when conditions are favorable during the summer. It grows about three inches tall, has a fleshy cap about three inches broad, generally white, sometimes reddish or brownish above and pink beneath. Its stem does not rise from a cup-like base as does that of Amanita phalloides. It is generally gathered in the "button" stage, that is, before the cap has expanded. Among its near relatives the best known is probably the horse mushroom (A. arvensis) which is much larger, whiter above, lighter below, the gills being white when young, but otherwise resembling the common species. Other prized edible relatives are: A. silvicolus, smooth, yellowish-white, with a long stem growing in the woods; A. rodmani, white, short and thick-stemmed, found in hard ground, as in city streets; and A. fabaceus, reddish-brown and long-stemmed, with an almond flavor and odor, which grows in greenhouses and on compost heaps. This species has been successfully cultivated.
Success in mushroom growing seems to depend more upon the individual grower than upon the method, since two growers may each succeed equally with very different methods. The essentials seem to be decaying organic matter in abundance, uniform but not excessive moisture, and equable rather low temperature. The most popular places for cultivating this plant are caves, abandoned mines, and quarries, cellars, pits and similar places, where the temperature is naturally suitable or may be artificially controlled. The beds are usually made by spreading a layer of well rotted manure and loam over a firmly packed deep layer of fresh horse-manure. After the violent heat of fermentation has passed and the temperature has fallen to or below 90°F., the mushroom "spawn" is planted. This spawn consists of the mycelium of the fungus in bricks (English) or flakes (French) made of equal parts of horse and cow manure and loam; it is a commercial article and its manufacture constitutes a business distinct from mushroom growing. After sowing, the bed is kept moist by mulching with straw or covering with mats which are replaced in about ten days with a layer of loam about two inches deep. In America the mushroom is rarely cultivated out of doors; in Europe it often is, the temperature and moisture there being more favorable. It is frequently found growing wild as in the vicinity of Petrolea, Ontario, Canada, in sufficient quantities to make commercial shipments profitable.
Besides the species already mentioned, sev- eral common American species are among the most desirable edible fungi. Coprinus comatus, the horse-tail or shaggy-mane mushroom, grows sometimes six inches tall, has a nearly cylindrical white shaggy cap with often black scales, and white gills when young, but these turn black and liquefy with age. It is commonly found in lawns, waste places, rubbish heaps, etc., from midsummer until the coming of frost, especially after showers. C. atramentarius, the ink-cap, resembles the preceding in general appearance and places of growth. C. micaceus, the glistening coprinus, is a brownish species smaller than the preceding. It grows upon decaying wood. Lepiota procera, the parasol mushroom, and L. naucina, the smooth lepiota, grow in lawns, pastures and occasionally in gardens. They have white spores and a ring on the stems, to which the gills are usually not attached. Cantharellus cibarius, the chantrelle, grows about three inches tall, measures nearly as much across the cap, has an irregular top-shaped yellow or orange cap, and has much-branched gills. It grows upon the ground in woods. Marasmius oreades, the fairy ring, or champignon, is a small cream-colored or reddish species, which tends to grow in circles upon lawns and pastures. It is rather tough and solid, but is valued for its nutty flavor and its drying qualities. Its gills are alternately long and short. Lactarius deliciosus has an orange cap, an orange milky juice, and with age shows greenish tints where bruised. Several other related species are highly valued by epicures, for example, L. volemus, with a white sweet juice and orange cap; L. corrugis, a darker species, even dark brown. Boletus edulis, the edible pore-mushroom, has a yellowish or brownish cap, with convex tubes which change with age from white to greenish yellow. It is commonest in chestnut, pine, and oak woods during autumn. Fistulina hepatica, the liver-fungus, grows upon decaying wood, is stemless and of irregular form, red, succulent and fibrous. It is often called beefsteak-fungus on account of its edible qualities. Morchella esculenta and several relatives, popularly known as morels, are of various colors, but usually grayish or yellowish. The top somewhat resembles honeycomb, which makes them easily recognized. Tbey delight in potash and are common where the land has been burned over or wood-ashes have been thrown; also in orchards and woods. Lycoperdon giganteum and other species of puffballs, which are common in pastures, are considered among the best edible fungi if used while still white. They are more or less globular in form. The species mentioned sometimes attains a diameter of several feet.
Mushrooms are often said to be equal to meat in nutritive qualities, but these statements are not warranted by analysis, which show that fresh mushrooms contain about 88 per cent of water, 3.5 per cent of protein, 6.0 per cent of nitrogen-free extract, and generally less than one per cent each of fat, fibre and ash. The protein content is therefore less than one fifth that of porterhouse steak, less than one third that of dressed codfish, and but little more than one-fourth that of hens' eggs. Indeed, according to analyses, they seem to be inferior to most vegetables. Their chief value is therefore in their flavors, which vary with individual species as much as among higher plants. They are eaten by various animals (see Fungus-Eaters).
Bibliography.-- Falconer, 'How to Grow Mushrooms' (1892); Falconer, 'Farmers' Bulletin No. 57,' U. S. Department of Agriculture, Washington, 1897; Farlow, 'Some Edible and Poisonous Fungi' in United States Department of Agriculture Year Book (1894); Peck, 'Mushrooms and their Uses' (1897); Dallas and Burgin, 'Among the Mushrooms' (1900}; Atkinson, 'Studies of American Fungi' (1900); McIlvaine, 'One Thousand American Fungi' (1900).