Murrill: Boletaceae of North America 141 



ellipsoid, smooth, ochraceous to yellowish-brown: stipe solid, ex- 

 cept in one or two species, even or reticulated, exannulate. 

 Type species, Ceriomyces crassus Battar. 



Stem shaggy and lacerated, with reticulated furrows. 

 Pileus dry, tomentose or reddish-pilose. 

 Pileus viscid, glabrous. 

 Stem smooth or reticulated with veins. 



Tubes white, not stuffed when young and not 

 turning blue when wounded, colored at 

 maturity with the yellowish-brown spores ; 

 pileus glabrous. A few subtomentose 

 species have whitish tubes when young. 

 Stem smooth, pileus white, smooth. 

 Stem reticulated. 



Pileus white, with deep chinks forming 



areolae. 

 Pileus gray, smooth. 

 Stem scabrous, pileus smooth, rarely white. 

 Stem conspicuously bright yellow near 

 the base. 



Stem entirely white or grayish-white. 

 Tubes flesh-colored ; cap small, floccose or 

 squamulose. 

 Pileus adorned with appressed yellowish 



flocci ; spores 14-16 X 5-6 fi. 

 Pileus adorned with conspicuous dark purple 

 scales; spores 9-12 X 2-3 fi. 

 Tubes bright yellow, sometimes tinged with 

 scarlet, unchanging at maturity or in dried 

 specimens. 

 Stem smooth, pileus glabrous. 



Stem 2 cm. thick; spores 15 X 6 fi. 

 Stem less than 1 cm. thick ; spores 

 10 X 4/"- 



Stem reticulated, pileus and stem covered 

 with a bright yellow or scarlet tomentum 

 or pulverulence. 

 Tubes some shade of yellow or brown, usually 

 becoming darker with age. In C. fumo- 

 sipes, C. sordidus, and C. Roxanae, the 

 tubes are whitish when young. 

 Parasitic on species of Scleroderma. 

 Found in clusters on roots and stumps of 



pine ; pileus bright golden-yellow. 

 Found on the ground, rarely on wood much 

 decayed and then not in clusters. 

 Tubes stuffed when young, their mouths 

 usually white ; pileus usually gla- 

 brous. 



C. Russellii. 

 C. Betula. 



3. C. albellus. 



C. frustulosus. 

 C. griseus. 



C. chromapes. 

 C. scaber. 



8. C. conicus. 



9. C. V anderbiltianus. 



10. C. flaviporus. 



11. C. auriporus. 



12. C. auriflammeus. 



13. C. parasiticus. 



14. C. hemichrysus. 



