40 BULLETIN 175, U. S. DEPARTMENT OF AGRICULTURE. 



Strobilomyces strobilaceus. 



Cap hemispherical or convex, shaggy from numerous coarse, blackish scales, 

 margin more or less appendiculate from the scales and fragments of the veil,- which 

 covers the tubes in the young plant; flesh at first whitish, changing to reddish, then 

 blackish where wounded ; tubes adnate, at first whitish, becoming blackish with age, 

 mouths large, angular, changing color like the flesh; stem even or tapering above, 

 sulcate at the top, scaly, colored like the cap. 



Cap 2 to 4 inches broad; stem 3 to 5 inches long, 4 to 10 lines thick. (PI. XXXII, 



fig- 2.) 



This fungus occurs commonly in woods and along roadsides, siDgly, in small groupc, 

 or occasionally cespitose, from early summer until autumn. It is considered edible, 

 but is not attractive. 



FOMES. 



The genus Fomes is distinguished among the Poryporaceae by the 

 hard, woody character of the species. The hymenophore is bracket 

 shaped; the tubes are much elongated and stratified, one stratum 

 developing annually. Fomes contains no edible species, but com- 

 prises many serious tree-destroying forms. 



Fomes applanatus. 



Cap smooth, cinnamon brown, becoming hoary, horizontal, flattened, shelflike, 

 concentrically zoned, semicircular, broadly attached, margin thickened, first white, 

 later becoming brown; hymenium flat, pores small, mouth white, changing to brown 

 when bruised; internal structure of fibrous-spongy texture, brown in color. 



Cap 2\ to 8 inches broad, 2 inches or more thick. 



This species is perennial and of common occurrence on various deciduous trees. 



Fomes lucidus. 



Cap horizontal, irregularly kidney shaped, blood red, surface uneven, coarsely 

 grooved, polished, corky, light in weight; stem lateral, length variable, polished, 

 same color as the cap; tubes small, white, then tan. 



Cap 2 to 6 inches broad. 



This fungus is of wide distribution and quite common occurrence, appearing on logs 

 and trunks. It is easily recognized on account of the varnished appearance of the cap 

 and stem. 



POLYPORUS. 



Species belonging to the genus Polyporus present considerable 

 variation in stem, form, and texture. The stem may be central, ex- 

 centric, or absent, the hymenophore circular, reniform, or hoof shaped, 

 azonate or grooved, and the substance fleshy, soft, corky, or woody. 

 This genus is distinguished from Polystictus by the thicker cap and 

 from Fomes by the nonstratose pores. Species of this genus are 

 widely distributed, and representatives may be found from the North 

 to the Tropics. Polyporus contains a few edible species and many 

 wound parasites, species injurious to economic and ornamental trees. 

 Wound parasites are fungi which have gained entrance to the interior 

 of a tree or host through some unprotected surface resulting from 

 lightning, insect attack, injudicious pruning, or some other agency. 



