American Boletes 3 



3. Gyroporus subalbellus Murrill 



Pileus convex, rather thick, scattered, 5 cm. broad; surface 

 dry, smooth, finely tomentose to glabrous, pale-isabelline; 

 margin entire, fertile; context spongy-fleshy, easily drying, 

 whitish, unchanging; tubes nearly free, longer than the thickness 

 of the context, mouths light-yellow, unchanging; spores ovoid, 

 smooth, hyaline under a microscope, 7 X 4.5 fi; stipe ventricose, 

 thick, distorted, smooth, pale-isabelline or nearly white, hollow, 

 7 cm. long. 



Found once on sandy soil in mixed woods at Ocean Springs, 

 Mississippi. 



2. TYLOPILUS P. Karst. 



Hymenophore annual, terrestrial or rarely epixylous, centrally 

 stipitate; surface dry, glabrous or minutely tomentose; context 

 white, fleshy, sometimes bitter; tubes small, angular, white, 

 becoming flesh-colored from the spores, not covered with a veil; 

 spores oblong-ellipsoid, smooth, rosy or flesh-colored, rarely 

 inclining to ferruginous; stipe solid, even or reticulate. 



Pileus yellow to brown. 



Sporophore large; stipe i cm. or more thick. 



Context decidedly bitter. i. T. felUus. 



Context not bitter. 2. T. indecisus. 



Sporophore usually small; stipe about 5 mm. thick, never 



reticulate. 3. T. gracilis. 



Pileus black or blackish; tubes becoming blackish when wounded. 4. T. alboater. 



I. Tylopilus felleus (Bull.) P. Karst. 



Pileus thick, convex, usually 8-15 cm. broad, sometimes 

 reaching a diameter of over 40 cm.; surface smooth, glabrous, 

 variable in color, usually some shade of tan or chestnut, often 

 pink or purplish when young; margin entire, concolorous; 

 context white, often tinged with pink where wounded, at first 

 firm but soft and yielding in older specimens, decidedly bitter, 

 especially when young, sometimes losing its bitter taste with age ; 

 tubes adnate, depressed, i-r2 cm. long, slender, white, colored at 

 maturity with the flesh-colored spores, mouths angular, of 

 medium size, edges thin, entire; spores fusiform, smooth, flesh- 

 colored, 8-1 1 X 3-4 fi', stipe cylindric, enlarged below, glabrous, 

 subconcolorous, usually reticulate above, and sometimes entirely 

 to the base, firm, solid, becoming spongy in large specimens, 

 5-12 cm. long, 1.5-2.5 cm. thick. 



Extremely common in woods throughout temperate North 

 America, often reaching a foot or more in diameter. It is very 

 bitter and therefore inedible. 



