94,129
edits
Changes
From Gardenology.org - Plant Encyclopedia and Gardening Wiki
Jump to navigationJump to searchno edit summary
Mushrooms can be also used for [[dyeing]] [[wool]] and other natural fibers. The [[chromophore]]s of mushrooms are organic compounds and produce strong and vivid colors, and all colors of the spectrum can be achieved with mushroom dyes. Before the invention of synthetic [[dye]]s the mushrooms were the primary sources on dyeing textiles. This technique has survived in Finland, and many [[historical reenactment|Middle Ages re-enactors]] have revived the skill again{{Fact|date=April 2007}}.
Mushrooms can be also used for [[dyeing]] [[wool]] and other natural fibers. The [[chromophore]]s of mushrooms are organic compounds and produce strong and vivid colors, and all colors of the spectrum can be achieved with mushroom dyes. Before the invention of synthetic [[dye]]s the mushrooms were the primary sources on dyeing textiles. This technique has survived in Finland, and many [[historical reenactment|Middle Ages re-enactors]] have revived the skill again{{Fact|date=April 2007}}.
Some fungi, types of [[polypore]]s, loosely called mushrooms, have been used as fire starters (known as [[tinder fungus|tinder fungi]]). [[Ötzi the Iceman]] was found carrying such fungi. Mushrooms, and other [[fungi]], will likely play an increasingly important role in the development of effective biological remediation and filtration technologies. [http://www.USPTO.gov The US Patent and Trademark office]can be searched for patents related to the latest developments in [[mycoremediation]] and [[mycofiltration]].
Some fungi, types of [[polypore]]s, loosely called mushrooms, have been used as fire starters (known as [[tinder fungus|tinder fungi]]). [[Ötzi the Iceman]] was found carrying such fungi. Mushrooms, and other [[fungi]], will likely play an increasingly important role in the development of effective biological remediation and filtration technologies. [http://www.USPTO.gov The US Patent and Trademark office]can be searched for patents related to the latest developments in [[mycoremediation]] and [[mycofiltration]].
== Standard Cyclopedia of Horticulture ==
{{Inc|
Mushroom. The best usage sanctions the use of the word "mushroom" as a comprehensive term applicable to any and all of the higher fleshy fungi, whether good, bad, or indifferent with respect to edible qualities. With this usage it is then proper to speak of edible, inedible, and poisonous mushrooms of all types. From some quarters there is an inclination to regard only the agarics, or more especially the centrally stalked gill bearing Agaricaceae, under this name; thus we would have the field agaric, or field mushroom, the fly agaric, or fly mushroom, and so on. In a commercial sense, Agaricus campestris and the allies of this species are everywhere in America the dominant, and usually the only species of interest; so that among certain classes of persons it is not strange to find a tendency toward the restriction of the word to the commoner cultivated forms. The same persons with wider experience would doubtless abandon this usage, and employ the above- mentioned broader application now more generally used, which is also the one of the "mushroom" books.
Another use of the term is as a counterpart of toadstool,—"mushroom" denoting any edible species, and "toadstool" all the inedible or at least poisonous ones. With this criterion we would collect and throw into the "mushroom" basket all species as fast as they might in some way or other receive approval, and we would cast into the toadstool limbo all uncertain or untried and dangerous forms. On the basis of such distinctions, applied to European conditions, there might be on the markets of Munich, Germany, about fifty species for sale as "mushrooms," since this number is approved by the authorities; but in Berlin, at the dictation of stricter tastes, or rules, the number of recognized "mushrooms" would be scarcely half that of Munich. "Toadstool" is a term which might well be held sacred to the fairy tales of mushroom life.
It seems probable that mushroom is derived from the old French mouseron or moucheron, now mousseron. An obsolete English form is musheron, while mushrump and mushrome have also been used. Among consumers of French canned "champignons" (fungi) there seems to be the feeling that this general term is used only for the cultivated forms, but this is merely a special trade use, and even in popular mushroom books the cultivated forms are carefully distinguished as "champignon de couche.
The only mushrooms cultivated extensively in Europe or America are the "common mushrooms," or field mushrooms, consisting probably of several closely related species, which are usually designated Agaricus campestris. In reality, there is a group of species, including at least A. arvensis, A. campestris and its near relatives, A. villaticus, probably A. Rodmani and A. fabaceus, any of which may be cultivated. It is not too much to hope that in time representatives of several other genera of the fleshy fungi may be cultivated for special purposes, but it is doubtful whether any species in culture would yield more abundantly than do the forms now grown. These species closely resemble one another in general characteristics and in life history, so that a description of a common type of A. campestris will define all with sufficient accuracy for the present purpose, and it will indicate in general the terminology of all the Basidiomycetes, that is, the class of fungi which contains the larger part of the fleshy forms.
The full-grown expanded plant is somewhat umbrella-like, with a central stalk (stipe) supporting a rather thick cap (pileus). The stem may be from 2 to 5 inches in height, about 1 inch in diameter, and above the middle there is typically a ring or annulus, but there are no other appendages about the stem. The cap bears on the under surface the gills, blade-like lamellae reaching for the most part from near the stem to the periphery of the cap. When the cap of the young mushroom begins rapidly to expand, it breaks away from its attachment to the stem, and the veil of tissue which has hidden the gills from view is ruptured at the periphery of the cap, leaving the ring or annulus already mentioned. When the gills are first disclosed they are of a beautiful pink color, but with age they darken and ultimately become brown-black.
The coloration of the gills referred to is due chiefly to the formation of spores or propagative cells, in large number. If one places the cap of a maturing mushroom on a piece of white paper, gills downward, protecting the cap from rapid drying out, a perfect spore print of the brown-black spores may be made. The number of these produced by a single mushroom expressed in figures is too great to be adequately grasped. The spores are small ovoidal cells, as shown in Fig. 2407, and they are borne upon club-shaped structures termed basidia,—these being organs which are characteristic of the whole class of the Basidiomycetes. The entire surface of the parallel gills is studded with the basidia, each basidium bearing from two to four spores.
Vegetative and fruiting stages.
In the open the spores doubtless germinate, but the conditions for their germination are not so well understood that they can be readily duplicated in the laboratory. At any rate, germination of the spores yields a mycelium or thread-like growth that is characteristic of most fungi. The development and growth of the mycelium in rich earth, compost, or manure yields a characteristic "spawn, for "spawn" is merely the abundant development of the mycelium, or vegetative stage of the fungus, in any suitable substratum. In this connection it is well to note that the mycelium of other fungi may invade a great variety of substrata. Rich earth, the moist leaves of the forest floor, fallen timber, and even the trunks of living trees are all invaded by a variety of species, each having its particular growth-requirements. Fresh spawn of Agaricus campestris has a fine aroma of mushrooms combined with that of almonds. By this aroma alone it may be easily recognized, and therefore distinguished from the mycelium of common mould fungi. By pure-culture methods, mushroom spawn may also be developed from fragments of the tissue, as subsequently indicated. Spawn is appropriately called the vegetative stage of the fungus.
The mycelium not only absorbs from the substratum the necessary water, together with the organic and inorganic food materials necessary for its immediate growth, but obviously there is accumulated a considerable amount above the growth needs, which serves as a fine adjustment to the heavy demands for food made somewhat later when fruiting begins. With a vigorous development of spawn in earth or compost, fruiting, or mushroom formation, will proceed. At this time the threads of spawn become more strongly corded and matted, attended by the formation of spherical "pinheads," and the latter develop directly into the well-known "button" stages, the appearance and rapid development of which give such satisfaction to the novice in mushroom-growing. With the increase in size of the button and the differentiation of gills, there is next a rapid expansion of the cap and the elongation of the stem, followed by the rupture of the veil. The mushroom is then full grown, at which time the shedding of spores begins.
Mushroom-culture.
In times past, it has been the custom to regard mushroom-growing as more or less of a mystery. It was therefore considered impossible to lay down specific rules for the guidance of others. This was due primarily to the fact that there had been very little experimental work from which to deduce the principles on which successful culture depends. There is now no reason why an intelligent person should not be able to produce mushrooms successfully if he is able to give to his work the care and attention which would be bestowed upon the cultivation of delicate flowers or the rearing of poultry.
Within the past dozen years, sufficient has been done to demonstrate the fact that the general principles of production are comparatively simple. The limits of conditions permitting production are narrower than those usually applying to other horticultural crops, yet it is true that the principles in the one case are just as definite as in the other. To state this in terms of its causation, it may be said that many of the more important biological problems concerned in the growth of mushrooms are sufficiently understood to enable us to comprehend the meaning and relative values of the practices which have grown up about this industry, and in many instances to modify these practices advantageously. As a matter of fact, since mushrooms should be grown only in situations which permit the practical control of conditions—that is, of the substratum or compost, the amount of moisture, the temperature, and other factors of the environment,—it should now be, and in the hands of many growers is, a more certain crop than many others commonly regarded as table necessities.
It is no uncommon thing to hear the question asked, "Why is it not possible to produce mushrooms successfully in fields and lawns? This question might be answered by anyone who reflects for a moment on the commercial success or failure of the pasture and lawn occurrence of mushrooms. One could predict that dandelions would be a successful lawn crop because whether one wills or no they are produced on our lawns in quantity, and sometimes they threaten to take possession where they may not be wanted. Mushrooms also occur in the lawn and field, but how sporadic and unreliable is the supply! One expects to find them in the early fall, but if they are not found, or occur in very limited quantity, it is easy to explain their absence on the ground of insufficient rain, unexpected cold weather, early summer drought, or other obvious causes. This merely indicates that mushrooms are not in any way commercially successful in such situations.
Mushrooms are indeed very sensitive to conditions, and commercial out-of-door culture is possible only in a region where the temperature conditions are fairly uniform throughout a considerable period of tune. Moisture is not quite so important, because even hi the open this often may be adequately controlled. Out-of-door culture is practised to a limited extent in England and in France, but in no section of the world is the common cultivated mushroom grown in the open successfully to compete with the product produced in mushroom-houses, cellars, or caves. Owing to the overwhelming importance of the indoor culture, therefore, it is only necessary to describe this as of commercial importance.
It was stated above that rules may be laid down for the cultivation of this crop. Rules must be in a measure arbitrary if they are to be successfully applied by the beginner. One who has mastered the principles may vary these advantageously for all changes of conditions. The more important factors involved in mushroom-growing, and about which recommendations must center, maybe enumerated as follows: compost, spawn, temperature, moisture, and sanitation.
Mushrooms, families of.
The cultivated mushroom is one type of the Agaricaceae, a family in which the spore-bearing, or fruiting surface (hymenium) is in the form of leaf-like plates, or gills. The spore prints of the fifty or more genera of this family vary in color from near black through all shades of brown and ochre to pure white.
Agaricus campestris, the common cultivated mushroom or field mushroom, has already been described. It is important to note for this, as for all species of the genus, the brown-black spores, the central stalk, the characteristic ring or annulus, and the gills changing from pink or light brown to brown-black free from the stem. In general, A. campestris possesses a simple ring, the stem is fairly uniform in diameter, and the cap varies from a cream-color to various shades of brown or gray-brown. The upper surface is usually smooth, but with alternate wet and dry weather or, as a result of the growth in rooms with variable artificial heat, it may be broken into more or less diamond-shaped areas exposing the white flesh. There are probably several cultivated varieties of this species, but it is often difficult to determine whether a given variety in culture belongs to this or to some related species. Three trade forms—based largely on color—are generally recognized, but within these color limits there are undoubtedly many varieties. The three trade names referred to are: "Alaska," relatively small, white or very light gray forms; "Bohemia," large brown varieties, one of which at least may be A. campestris; and "Columbia," which is the name for the large cream-colored forms which may apparently be referred to one of several species.
Agaricus arvensis, ordinarily known as the horse mushroom, has much the same season and habitat as A. campestris, and forms occur which seem to be inter- grading. Typical forms of the horse mushroom are larger and stouter than the field mushroom and distinguished from the latter by the possession of a double ring. There is some diversity of opinion regarding pileus (color) characters but in any event there would appear to be several varieties in cultivation which may be properly referred to this species. Under cultivation the writer has been unable to find any better flavor in A. campestris than in A. arvensis. A. Rodmani and A. villaticus are closely related to A. arvensis and A. campestris, but there is some doubt as to whether either of these should be regarded as distinct species.
Agaricus fabaceus (A. subrufescens) is the almond- flavored and almond-fragrant mushroom, sometimes found in greenhouses or in flowerbeds. This species is readily distinguished by (1) the long-persistent membranous veil, the lower surface of which is covered with soft frosty scales; (2) the red- brown to gray- brown (with age) pileus; and the enlarged lower part of the stem. It has been cultivated, but requires a higher temperature than A. campestris and is said to be less prolific. It deserves further trial. The spawn grows vigorously in the usual bricks. A. placomyces is a woodland species, and it is sometimes found from early summer until late fall. The cap is large, flat, and thin, appearing smoky above from the presence of numerous small, dark scales, which are closer together near the center. The veil is like that of A. arvensis, and the base of the stem is enlarged. The writer has made spawn of this species, and cultivated it in small quantity.
Agaricus silvicola, also an inhabitant of woods, is almost pure white except as to gills. It is sometimes tinged with yellow, and is always a rather small species, occurring in the summer. Its value in cultivation could be only with relation to its resistance to high temperature.
The question of temperature-resistance is an important one, however, and the discovery of an acceptable edible species which might be grown at from 60° to 70° F. would make it possible to extend the mushroom- growing season to ten or eleven months.
Coprinus.—Aside from Agaricus, Coprinus is the only other genus of the Agaricaceae with black spores which is sufficiently important from an economic standpoint to require consideration. The genus is characterized more particularly by the deliquescence of gills and other parts of the pileus at maturity to an inky black liquid. There are three edible species of common occurrence, appearing usually in lawns in the spring. C. comatus (Fig. 2413), the shaggy-mane mushroom, is the largest, and one of the best of the fungi. The whole plant is often 6 inches in height, with a cylindrical cap frequently not less than 3 inches long and 1 ½ inches in diameter. The name is derived from the shaggy scales on the pileus. As the plant approaches maturity the gills are of a salmon-color and there is a free or movable ring. C. atramentarius, the true ink- cap, is a shorter form than C. comatus, and it commonly occurs in clusters. The shorter, oval cap is slaty gray in color, due to the background of dark gills showing through the hygrophorus tissues. C. micaceus is much smaller than either of the preceding, and occurs often in solid phalanx covering several square feet of space about old stumps or over decaying roots. When young, the tan-colored cap is covered with temporary, glistening scales, like minute particles of mica. The only disagreeable feature about the Coprini is their deliquescence, but they are of fine flavor and quality, if eaten fresh.
Lepiota.— The genus Lepiota corresponds to Agaricus in general characteristics, except that the spores in the former are white. There are many species of this genus, of which the more important are Lepiota procera (the parasol mushroom) and L. naucinoides. Both are found widely distributed in lawns, fields, or meadows. The parasol mushroom is one of the most conspicuous of the edible agarics, standing frequently 10 inches high with a pileus often 5 to 6 inches in diameter, reddish brown in color, with darker blotch-like scales. The stem is delicate except for the bulbous base. The ring is large and free. L. naucinoides in prime condition is usually pure white. It is about the average size of the cultivated mushroom, but with a thinner cap and a stem more slender, thickening toward the base. One who is not an expert should remember that the deadly amanita is also white. See Amanita, below.
Armillaria mellea, the honey agaric, commonly brownish yellow in general appearance, is typically an autumn plant growing in clusters about stumps and the bases of trees, or appearing through the sod over decaying roots. It is one of the more abundant mushrooms in wooded sections. In form, this plant differs from Lepiota largely in the fact that the gills are attached to the stem. The spores are white but the gills become discolored with age. This species is parasitic on a number of trees. The mycelium develops a characteristic cord-like, or rhizomorphic stage. This plant is acrid and disagreeable raw, but cooked it is said to be of good flavor.
Amanita.—The genus Amanita is interesting for two reasons: (1) because it contains some handsome species, which are quite likely to attract the attention of every beginner in identification; and (2) because among these species there are several which are the most deadly poisonous of all mushrooms. Unless one is an expert, therefore, it is well to learn the characters of the genus in order to avoid any inclination toward using them for food. The genus contains, it is true, several edible species, and when one knows them there is no danger. Amanita possesses all of the general characters of Lepiota, likewise certain additional ones which serve clearly to distinguish it. The white spores (and usually white gills), the annulus, and gills free from the stem are just as in Lepiota; but there is in Amanita also a volva, or universal veil, which in the mature mushroom appears usually as a cup at the base of the stem, and sometimes remnants of it are carried up by the pileus as frosty scales. In the button stage this universal veil is an outer skin or envelope, and as the plant expands it bursts through the envelope leaving more or less of cup or at least a basal ring at the base; and if the upper part of the envelope adheres to the cup, it is broken into mere scales, or frosty patches, as the pileus grows. Now if one pulls up an Amanita carelessly, the volva might not be detected. On the other hand the ring, or veil, might be broken, and then with a volva and no ring the plant might be mistaken for an Amanitopsis—a genus with many edible species. Young stages in meadows have been mistaken, indeed, for buttons of Agaricus campestris. The Amanita phalloides, deadly amanita (Fig. 2414), is widely distributed in the United States, occurring especially in woods and meadows. The plants may attain a height of 6 inches and a pileus diameter of 4 inches. In general appearance it might be mistaken for a Lepiota, especially L. naucinoides, as some forms of the species may be entirely white. As a rule, however, the upper surface of the cap is grayish, brownish, or greenish. Usually, there are no scales, at any rate no small scales, on the cap, and the volva is cup-like. A. verna, the destroying angel, is a pure white plant, regarded by some as one of the white forms of A. phalloides. A. muscaria, the fly agaric, is only somewhat less poisonous than those above mentioned. It is one of the handsomest mushrooms of the forest. The plant may be larger than A. phalloides, and the cap varies from yellow to orange- red in color, with frosty or creamy white scales or patches. In this species the volva is not so prominent, since the universal veil breaks transversely into a number of small incomplete rings, which remain at the base of the somewhat bulbous stem in the form of interrupted rings of scales. The gills and stem are white. A. Caesarea, the royal agaric, has also an orange-red cap, but in this species there is a very definite cap-like volva, and the gills of the plant are yellow to orange. This species has been much prized since the earliest historical times, but no one should attempt to use it who is not able clearly to distinguish the different species of Amanita.
Tricholoma personatum, the masked tricholoma, is a representative of a genus differing from Lepiota in possessing no ring, and further in having the gills attached to the stem, yet notched near the point of attachment. This species is usually pale violaceous or lilac when young, and the pileus is plane or distinctly wavy. The flavor is esteemed. It has been cultivated in experimental beds.
Clitocybe.—In this genus the spores are white and the gills are not only attached but decurrent upon the stem. Clitocybe velutipes grows in clusters about stumps and trees, and is readily recognized by the bright red- brown viscid pileus, the pale yellowish gills, and the dark stems clothed at the base with a growth of hairs velour-like in texture. This fungus is a late fall and winter mushroom, prized by many, in spite of an apparent toughness in the raw state.
Pleurotus.—The members of this genus which are of special interest horticulturally grow on decayed places in the trunks of trees, or on logs, and they are readily distinguished from all other white-spored agarics by the excentric stem. It is typically a clustered mushroom—the clusters being sometimes of enormous size. The plants are white or lightly tinted, and the gills are generally decurrent. Pleurotus ostreatus, P. sapidus, and P. ulmarius are the commoner large species, all of which are edible, but not keenly sought.
Lactarius, the mushrooms which yield a milky juice when the gills are cut or injured, is represented in our woods by several species, of which the commoner edible ones are Lactarius deliciosus and L. volemus. In form these plants are much like a Clitocybe, but the gills are not strictly decurrent. Lactarius deliciosus is yellow-buff or light orange, mottled with darker spots or zones, and the juice is orange-colored. The plant is often about 4 inches high and the pileus about 3 inches in diameter. L. volemus, a somewhat smaller plant, is of uniform color, brown-orange, or tawny, with white juice. The peppery lactarius, a large white species, is very acrid. Closely related to Lactarius is the genus Russula,—lacking the milky juice,- of which many species with pilei white, greenish, violaceous, or red are found in our woods in summer and early autumn.
Cantharellus cibarius (Fig. 2415). the chanterelle, is one of a group the members of which are barely agarics, for the gills are often almost vein-like, rounded on the margin and often reticulate. The chanterelle is uniformly yellow to orange in color, small, more or less unsymmetrical in form. It is also an inhabitant of the woods, and it is much used as a vegetable food in Europe.
Other Basidiomycetes.
It has been indicated that the larger part of the fleshy fungi are included among the Basidiomycetes, and while the Agaricaceae furnish the greater number of forms of paramount interest to the average layman, nearly all families of these fungi contribute showy or edible species—and some families numerous species. In the Polyporaceae and Boletaceae the spore-bearing surfaces are in the form of pores. In the genus Polyporus the plants are tougher in texture than those usually edible, and the larger number grow on wood and trees—some causing the more destructive diseases of wood and timber. One of the edible forms frequently observed and most conspicuous is Polyporus sulphureus, which forms immense clusters of sulfur-yellow and orange, bracket-like sporophores on a variety of trees and stumps. Many species of Boletus are edible, but some are to be avoided, and some positively toxic. Boletus edulis (la cepe, der Steinpilz) probably furnishes more than any other one species of the fresh wild fungi sold on the markets of European cities. Boletus subtomentosus (Fig. 2416) is not poisonous, but is of inferior quality.
Fistulina hepatica, often known as the beefsteak mushroom, is a juicy, fleshy species with red pileus. The plants are bracketed, and grow from the stumps of several hardwoods. The fungus is prized by many, and while widely distributed it occurs sparingly.
The Hydnaceae are characterized by a spore-bearing surface spread over teeth or spines arising cither from a cap-like pileus or from a tubercular or much-branched structure. Among the edible species Hydnum repandum possesses a pileus and true stem. It is of a smoky color and occurs in the autumn on the ground in moist woods. H. coralloides (coral hydnum) and H. erinaceus (satyr's beard) are both delicate white or creamy fungi—both found in the autumn, on logs or trees.
In moist wooded places there appear in the late summer and early fall along with Boletus, Russula, and other species, several members of the Clavariaceae (stag horn or fairy club fungi). In this family the spores are borne over the whole horn or club-like body. These are of various colors from buff to orange or sooty gray. All species which are of sufficient size to be usable are considered edible. Clavaria aurea (Fig. 2417), C. formosa, and C. botrytes are among the larger forms. In the Thelephoraceae, which include species more or less leathery in texture, the spores are on the lower or outer surface, where that may be distinguished. The horn of plenty, Craterellus cornucopioides, a smoky-blue horn shaped species, is practically the only edible species of interest in this family. The gelatinous fungi, including; the Tremellaceae; and allied families, are not of sufficient interest to require special description.
Among the Basidiomycetes in which the spores are differentiated internally, or remain long covered, the puff-balls (Lycoperdaceae) furnish a number of species of economic importance. All of these plants with white flesh are edible, and some are valuable food accessories. They should be eaten only so long as the flesh is white, and when discolored with age—normally due to the formation of the spores—they must be discarded. The largest species, Lycoperdon giganteum (giant puff-ball), frequently attains a diameter of 16 inches, while specimens over 2 feet in diameter have been reported. This species occurs in gardens and meadows. The flesh is pure white until practically full size is attained. Lycoperdon cyathiforme, the beaker-shaped puff-ball, is common in pastures in the fall. In the young stages the plants vary in color from creamy white to pink-brown, with white flesh. With the formation of spores it becomes purplish throughout, and leaves a purple beaker-shaped sterile basal part. This is perhaps the puff-ball of highest flavor, and consequently the one which should be known by all persons interested in edible mushrooms. Lycoperdon craniforme (Fig. 2418) is found in meadows or in open woods. At maturity the plant shrinks, and may become considerably furrowed, from which character the specific name is derived. Resembling smaller members of the Lycoperdaceae externally is a fungus, Scleroderma vulgare (Fig. 2419), which is black within, tough and inedible.
Ascomycetes.
While the larger part of the flesh fungi belong to the Basidiomycetes, nevertheless the few families of the Ascomycetes furnish some forms of special interest. The family Helvellacese includes the genus Morchella (morels), as well as Helvella (saddle fungi) and Gyromitra (contorted saddle fungi). There are several species of morels often appropriately called sponge mushrooms, the latter designation being given both on account of the color of the plant and the porous character of the pileus. The morels are widely distributed in the United States. All appear after the warm rains of the spring. They constitute, therefore, about the earliest edible mushrooms. The season is often limited to one or two weeks of favorable weather. Morchella esculenta (Fig. 2420) is a common species, and one which appears to be M. crassipes is frequently found in the Central States at least. The tuber family (Tuberaceae) includes all truffles, very aromatic subterranean fungi found for the most part in southern Europe, and there constituting a considerable article of commerce. The mycelium of these plants is associated with the roots of certain trees and shrubs, especially oaks. The species most highly prized are Tuber melanosporum, the typical French or black truffle, sometimes called the Perigord truffle, which is commercially much more important than all other species combined; T. aestivum, which is the summer truffle of France; and T. magnatum, a large, smooth species with onion-like flavor, which is the commoner form in Italy. The terfas, or false truffles (Terfeziaceae), are also subterranean fungi found associated with the roots of certain species of Cistaceae and Compositae. The regions of their occurrence are primarily semi-arid sections of northern Africa and localities in the Asiatic Mediterranean country. They are apparently the truffles of ancient times. The plants are spherical or ovoidal in form, and at maturity they have a general resemblance in size and texture to a potato.
}}
== Trivia ==
== Trivia ==
