Fam. n, Polyporaceae. 



Key to the genera of the Polyporaceae. 



A) Hymenium all exposed (i. e., a portion of the hymenium not in permanently 

 closed chambers. 

 B) Plants fleshy, not becoming tough in age, soon decaying. 

 a) Stipe central or nearly so. 

 BOLETUS. Stratum of tubes easily separable from the pileiis, tubes rather long, 



mouths circular or angular. 

 BOLETINUS. Stratum of tubes not easily separable from the pileus, tubes as in 

 Boletus but usually shorter, mouths larger and radiating in rows from the 

 stipe. 

 STROBILOMYCES. Stratum of tubes not easily separable from the pileus, tubes 



as in Boletus ; outer surface of pileus tough, and torn into scales. 

 Gyrodon. Stratum of tubes not easily separating from the pileus, tubes as in 

 Boletus but very short, and mouths sinuous, gyrose-plicate. 

 aa) Stipe, or attachment, lateral. 

 FISTULINA. Tubes separate from each other, though crowded. 

 Bresadola. Tubes spurios, formed by the gills turned both horizontally and ver- 

 tically (possibly not a good genus). 

 BB) Plants tough (sometimes fleshy when young), leathery, fibrous, mem- 

 branaceous, woody, or corky, 

 a) Tubes at the mouth rounded, angular, sinuous or labyrinthiforra, not 

 in radiating rows (except in forms of Daedalea confragosa). 

 b) Tubes in stratum unlike that of the hymenophore, but not separable, 

 evenly inserted in the pileus (or if unevenly, then substance of 

 pileus not passing between the tubes unchanged. 

 POLYPORUS. Tubes formed evenly, crowded, not stratose, plants tough 

 (sometimes fleshy or soft when young, but becoming tough in age) ; 

 stipitate or sessile, or lateral, sometimes resupinate, but then pileus 

 thick (i. e., substance between tubes and substratum). 



FOMES. Tubes formed as in Polyporus, but often stratose; plants woody 



from the first, sessile, dimidiate, or in some, lateral. 

 POLYSTICTUS. Tubes not stratose, frequently maturing centrifugally, at 



first superficial, punctiform ; plants coriaceous, membranaceous ; 



pileus thin and as compared with Polyporus. (Some species like P. 



pergamenus have the tubes split into teeth thus resembling Irpex). 

 PORIA. Plants entirely resupinate, indefinitely spreading ; pileus very 



thin or none (i. e., tubes seated on a thin layer of mycelium), waxy, 



leathery, or membranaceous. (Do not confuse with resupinate forms 



of Polyporus). 



MUCRONOPORUS. Tubes studded with reddish brown spines intermin- 

 with the basidia, otherwise as in Polystictus (and also as in Polyporus 

 and Pomes). An unnecessary genus. 



Laccocephalum. Pileus woody, stipe central ; tubes cylindrical, crowded, not 

 separable from the hymenophore. 



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