AGARICALES 



109 



gins of the pileus; the stem is solid and of a whitish color and is 

 marked somewhat like that of B. scabcr. Several species of Bo- 

 letus are canned in Germany and sold under the name of Stein- 

 pilze. 



Some of the species of Boletus are very beautiful. A very 

 common yellow species (B, ornatipes) has the stem elegantly 

 reticulated. B. Ravenelii, more common in the Southern States, 

 is a brilliant yellow and is dusted over with yellow powder. B. 

 Frostii, of the section Luridi has an elegant red and yellow mot- 

 tled pileus and the tubes have the characteristic bright red mouths 

 of the section. It is a common species of eastern New York and 

 New England, and probably has a wide distribution. B. auri- 

 porus has a pileus and brilliant golden yellow ports. Many of 

 the species change the color of the flesh to a brilliant blue on ex- 

 posure to the air ; while this is not a sure sign of an injurious 

 species, it is to be looked upon as a suspicious character. 



The species of Boletus are most abundant during the moist 

 rains of late summer and early autumn, ranging in the Northern 

 States from July to October and in the Southern States appearing 

 somewhat earlier if there is sufficient soil moisture, as well as 

 somewhat later than farther northward. 



Family 7. Agaricaceae. 



This family is the largest and most widely distributed of all the 

 families, containing some five thousand described species. Over 

 twelve hundred are known from Great Britain alone, and about as 

 many have been reported from the United States, where careful, 

 exhaustive research has been made only in a few limited areas 

 and by a very few individuals. 



The common edible mushroom of the fields and markets, 

 Agaricus cainpestris, is a type of this family and a somewhat de- 

 tailed account of its character may be given with side references 

 to structures illustrated by species of allied genera. The growing 

 or vegetative portion of the fungus consists of wide spreading 

 hyphae forming a tangled mycelium which permeates the soil in 

 search of decomposing organic matter which serves as food to the 

 plant. This mycelium, grown in compost and dried, forms the 

 so-called spawn of the seed dealers from which the ordinary cul- 



