IO4 



BASIDIOM YCE TES 



H. echinaceus is white, becoming yellowish in the form of a 

 tubercular mass often six to eight inches broad with straight equal 

 spines which are sometimes nearly two inches long. 



H. caput-medusae is also tubercular, but changes from white to 

 a smoky or ashy tint and is usually contracted into a stalk be- 

 hind ; it has short distorted teeth above and long uniform ones 

 below. 



A large number of the species of Hydnnm are resupinate, some 

 of them growing in the form of thin layers of mycelium expanded 

 into a membrane on which a few spines are borne ; others form 

 larger areas several feet in extent, growing underneath fallen logs.* 



Family 5. Polyporaceae. 



This family contains the pore-bearing forms whose pores are 

 usually permanently united to the context y and to each other. 

 A few of the members of the family are fleshy, some, indeed, 

 being edible, but by far the greater part are leathery, corky, mem- 

 branous or woody. They form the more conspicuous bracket- 

 fungi shelving from dead or dying trunks and logs, some of them 

 attaining a very large size ; others growing in similar situations 

 are very small or even minute. Nearly six hundred species have 

 been reported from America. 



The genera can be distinguished as follows : 



I. Pores minute and round or larger and angular. 2. 



Pores forming labrinthine passages or becoming lamella-like plates. 8. 



Pores reduced to shallow pits separated by narrow ridges, folds or 



reticulations ; more commonly resupinate. MERULIUS. 



* Fries used the following subdivisions for many of his genera of which 

 Hydmim possesses common examples of all. A statement of their 

 characters will show the diversity of the genus as here limited : 



I. MESOPUS : with a central stem supporting a pileus. 



II. PLEUROPUS : with a lateral or eccentric stem supporting a pileus. 



III. MERISMA : compound or multiple forms united to one base. 



IV. APUS : pileate, semicircular, sessile. 



V. RESUPINATI : without a pileus, the slender membranous base 

 attached flatly to the hymenium. 



t In Gloeoporus the layer of pores sometimes peels off from the context 

 when rather young and moist. 



