KEY TO THE SUBFAMILIES AND GENERA OF FAMILY BOLETACEAE 519 



nium, spores with a germ pore and often truncate at one end, often 

 over 20 n in length; no clamp connections observed. 



Subfamily Strobilomyceteae 

 Spores globose to short ellipsoid; spore print black; tubes white or gray at 

 first, becoming darker; pileus and stipe warty, woolly or spinose- 

 squarrose. Strobilomyces 



Spores more elongated; spore print reddish-brown; tubes white to cream 

 color, becoming pink vinaceous to sordid gray to porphyry brown; 

 spores smooth or with short warts or spines perforating the exospore. 



Porphyrellus. 

 Spores elongated (or short elliptical in species with reticulate markings); 

 spore print olivaceous brown to blackish but not reddish; spores 

 smooth or with longitudinal wing-like ridges or ribs, or with warts, or 

 reticulately marked. Boletellus 



Spores pale pink to yellowish or ferruginous or olive brown; germ pores not 

 visible; spores mostly less than 20 n in length. 



Subfamily Boleteae 

 Tubes short (see also Phlebopus), radially elongated, often with the radial 

 walls higher than the cross connections; clamp connections regularly 

 present; stipe sometimes eccentric or lateral. 

 Hymeiiophore depressed or subfree around the apex of the stipe. 

 Spore print yellow. Gyroporus 



Spore print olive brown. Phaeogyroporus 



Hymenophore more or less arcuate-decurrent. 



Veil present. Paragyrodon 



Veil absent. Gyrodon 



Tubes long (see also Phlebopus, below) ; clamp connections entirely lacking or 

 not numerous. 

 Pores radially elongated or lamellate (see also Suillus under Pores round) . 

 Pores distinctly lamellate, but always with low anastomoses; veil lack- 

 ing; spore print olive brown. Phylloporus 

 Pores radially elongated but not lamellate; veil present; pileus rarely 

 viscid; stipe without glandulae; spore print olive brown. 



Boletinus 

 Pores radially elongated but not lamellate; pileus always viscid; without 

 veil, or if with veil then pores round; stipe frequently with glandulae; 

 spore print olive brown. Suillus 



Pores round; spores olive brown (see also Suillus under Pores radially 

 elongated). 

 Pileus always viscid; veil present; stipe frequently with glandulae. 



Suillus 

 Pileus tomentose; rarely viscid; stipe without glandulae. 



Xerocomus 

 Surface of pileus and stipe more or less pulverulent; spores small, ellip- 

 soidal to ovoid; tubes long, adnate or depressed around stipe; veil 

 sometimes present; stipes mostly cylindrical or only slightly thickened 

 downward, often viscid. Pulveroboletus 



Surface of pileus not noticeably pulverulent, sometimes slightly viscid; 

 tubes short or of medium length; hymenophore arcuate, at least when 

 young, and somewhat decurrent; veil absent; spores small to medium 

 size; stipes frequently swollen- ventricose; not viscid. 



Phlebopus 



