Somewhat like the preceding in general appear ance are a few toothed fungi, which grow on decaying trunks or limbs. These plants belong to the genus Hydnum, and they are found only in wooded regions, usually in the presence of abundant moisture. The fungus body may consist of a very much branched structure, the branches ultimately terminating in teeth. The characteristic species are cream white and they are of good texture. The best known forms are the Coral Hydnum, H. coralloides, and the Satyr's Beard, H. erinaceus. There are also two important members of this genus which have an irregular umbrella shape, the lower surface of the pileus in these cases being studded with teeth (Fig. 709). Both species are edible and of good flavor. They are frequently found in unusual abundance in mountain woods, in situations favorable for the Clavarias above men tioned, in the late summer and early autumn.
If there is one group of the fleshy fungi well known to all who have had opportunities to know the products of the pasture and meadow, this group is that of the puffballs. The puffballs are all c ?ible, and many of the larger species are some of the most valuable of our fleshy fungi. If collected and used when the flesh is white, discarded always when old, or when the flesh has begun to change in color, no suspicious or injurious qualities can be assigned to this group. The larger species are sometimes very abundant, and a single plant may furnish a delicate accessory dish for a whole family. Among the valuable species several may be mentioned. Calsatia cyathiforme, the beaker shaped puffball, is common in pastures throughout the United States. It is a plant of the early autumn, and is most abundant when the season is moist and cool. It is a favorite food of insects, but since the latter are comparatively inactive during cool weather, that is the season when they are to be expected in greatest profusion. This puffball is at first white and later may become purplish brown, or white with a slight tint of brown. The flesh is firm and pure white even until full size is attained. The plant may attain a diam eter of as much as five or six inches. With age it becomes spongy, and the plant differentiates into a mass of purple-brown threads and spores ; this gradually wears away, leaving a purple-col ored basal cup or beaker, which may be found in the pastures for months after the V-11 spores have blown away. The Giant Puffball , (Calvatia gigantca) is also found in pastures, 4 but it may appear in gardens and meadows / as well. It has been found of a diameter of more than two feet, and can frequently be had sixteen to eighteen inches across. Thus far it has not been possible to cultivate any of these species of puffballs, but in recent years the use of these plants has become very much more general, perhaps because of the recognition of the very definite characters of the group. Even the
smaller members of the puffballs may be used when the flesh is white and tender.
An entirely different class of mushrooms, and one which indeed includes the truffles and terfas, is of further economic importance as furnishing, in practically all north temperate regions of the earth, some of the most highly prized of the mush rooms, namely, the morels. There are several spe cies of the morels, the chief one being Moschella esculenta (Fig. 710), the common morel (in German knot a as Morchel, and in French as Morille). In the United States this plant may pass under the name of "sponge mushroom," this fittingly describ ing the general appearance of the plant, for the morel is of a sponge-like color, and consists of a stem bearing a cap or head, which is thrown into folds or wrinkles, also suggesting very much the struc ture of a sponge. The plant is two to five inches in height and of very neat ap pearance. It is found chiefly in open woods, though it may also extend into grassy place s and orchards. Its season in the United States is from late April to early June, and in a particu lar locality it may come and disappear within a single week. It must therefore be sought as the earliest edible mushroom. With the exception of the truffle, more over, it is con sidered by the French the greatest delicacy among mushrooms, and it commands on the markets of Paris a price several times that of the cultivated mushroom.
Truffles and other subterranean forms.
Truffles are the fruit bodies, or sporophores, of subterranean fungi belonging to the family Tuber acme, of the class Ascomycetes. There are only six or seven species which, because of size and quality, may be considered of economic importance. These are all classed in the genus Tuber, as are also many small species.
The black or winter truffle (Tuber melanosporum, Fig. 711) is particularly abundant in France. It is preeminently the truffle of commerce, and con stitutes most of the best exported product. It is sometimes known as the Perigord truffle, and has made famous the markets of Perigord and Carren tras. This species has a wonderful aroma and flavor. Tuber eestivum, the summer tr iffle, occurs also in southern France, but chiefly in parts of cen tral France. The next important species is T. magnatum, a large species with alliaceous flavor, highly prized and abundant in Italy. Any of these species may vary in size from plants smaller than hulled walnuts to those larger than an orange, in extreme cases. The majority of truffles are dark brown or black, with a peculiar warty surface, but 7'. magnatu m is smooth and light, in color, some what resembling a spherical yam.