AMERICAN BOLETES 



Including species occurring in North America, Central America, 

 the West Indies, and all other islands between North America 

 and South America with the exception of Trinidad. The tropi- 

 cal representatives of the family are extremely limited, both in 

 number and distribution. 



BOLETACEAE 



Hymenophore annual, nearly always terrestrial and centrally 

 stipitate; context fleshy; hymenium poroid, fleshy, never gela- 

 tinous. 



Tubes not arranged in radiating rows (except in one or 

 two species of Boletus). 

 Spores hyaline, often becoming yellowish; stipe hollow, 



not reticulate. i. Gyroporus. 



Spores rosy or flesh-colored; stipe solid, usually reticu- 

 late. 2. Tylopilus. 

 Spores ochraceous to brown or black. 



Stipe neither glandular-dotted nor annulate. 



Mouths of tubes never uniformly red nor red- 

 dish-brown, tubes unicolorous. 3. Ceriomyces. 

 Mouths of tubes red or reddish-brown, tubes 



yellowish within. 4. SuiLLELLUS. 



Stipe either glandular-dotted or annulate. 



Stipe glandular-dotted, exannulate. 5. Rostkovites. 



Stipe annulate, glandular-dotted in some species. 

 Spores ochraceous to yellowish-brown, 

 smooth, usually oblong-ellipsoid. 

 Sporophore not covered with a yellow 

 powder. 

 Pileus smooth, viscid. 6. Boletus. 



Pileus floccose-verrucose, dry. 7. Boletellus. 



Sporophore covered with a conspicuous 

 yellow powder. 8. Pulveroboletus. 



Spores brownish-black, rough, subglobose. 9. Strobilomyces. 



Tubes arranged in radiating rows. 



Stipe exannulate. 10. Boletinellus. 



Stipe annulate. 11. Boletinus. 



I. GYROPORUS Qu61. 



Hymenophore annual, terrestrial, centrally stipitate; surface 

 dry, minutely tomentose to floccose-squamose; context white, 



I 



