Polyporaceae 



Boletus, shining. The stem increases in thickness above and downward. Peck, 

 Boleti of the U. S. 



B. badi'ceps Pk. badius, bay and head. (Plate CXVI, p. 420.) 

 Pileus firm, convex or somewhat centrally depressed when mature, dry, 

 velvety, obliquely truncate on the margin, bay-red or dark-maroon 

 color. Flesh white unchangeable, taste and odor mild, sweet, sug- 

 gestive of molasses. Tubes plane, adnate, white or whitish, becoming 

 dingy with age, the mouths minute. Stem e*qual or slightly swollen in 

 the middle, radicating, glabrous, solid, brownish. 



Pileus 4-8 cm. broad. Stem 4-5 cm. long, 1.5-3 cm. thick. 



Oak woods. West Philadelphia, Pa. August and September. Charles 

 Mcllvaine. 



The truncate or beveled margin of the pileus is a striking feature in 

 this species. It is about 4 mm. broad and as even as if cut with a 

 knife. Sometimes the surface of the stem ruptures transversely just be- 

 low the top, the liberated shreds above curling upward against the tubes 

 and those below curving outward and downward. In mature plants 

 brownish spots appear in the flesh of the pileus. "When cooked it is 

 of high flavor and tender as kidney," C. Mcllvaine. Peck, Bull. Tor- 

 rey Bot. Club, January 27, 1900. 



LACERI'PEDES lacerated stem. 



Stem elongated, coarsely pitted or deeply and lacunosely reticulated 

 in small hollows, the ridges somewhat intumescent in wet weather and 

 more or less lacerated, giving a rough or shaggy appearance to the stem. 



The species of this tribe are few, very closely allied and so far as 

 known are peculiar to this country. 



Pileus viscid I 



Pileus dry B . Russelli 



I. Stem red in the depressions, tubes tinged with green. . .B. Morgani 

 i. Stem pale-yellow, tubes not greenish B. Betula 



Peck, Boleti of the U. S. 



B. Rus'selli Frost Russell's Boletus. (Plate CXVIII, fig. 2, p. 436.) 

 PileilS thick, hemispherical or convex, dry, covered with downy scales or 

 bundles of red hairs, yellowish beneath the tomentum, often cracked in 



436 



