THE SAPROPHYTIC FUNGI OF EASTERN IOWA. 35 



Mad/sou, Wisconsin, by Prof. Wm. Trelease, constitute the 

 principal American literature on this subject. 



The group Gasteromycetes as a suborder of the order 

 Basidiomycetes ma}' be thus defined: 



GASTEROMYCETES {Fries) WiUd. 



Fungi, terrestrial or more rarely lignatile, attaining in some 

 cases great size, developed from more or less wide-spreading 

 mycelium which at the point of fructification converges to 

 produce the sporocarp and usually in rhizoidal fashion binds 

 it fast to the substratum; sporocarp consisting essentiallv of a 

 closed sac or peridium, generally double, within which is devel- 

 oped a variously modified hyphal structure the gleba, with 

 numerous hypha-walled secondary sacs or chambers lined or 

 filled by the basidiosporous hymenium; basidia various, bear- 

 ing apical or lateral spores often in fours; spores spherical or 

 elliptical, hyaline or variously tinted. 



The sub-order is variously divided into families by different 

 authors according as each recognizes some special distinction 

 in the manner in which the hymenium is enclosed. For 

 instance, Saccardo divides the sub-order into four families 

 Phalloidiccp, JVidulariacece, JLy coper dacecR and Hymenogastracece, 

 while Winter has six families, P/ialloidece, Hymenogastrece, Sch- 

 roder mcce, Tulostomece, Ly coper dinece and JViduIaricce. Morgan 

 combines these two schemes. His classification contains five 

 families, the Tulostomece and the Lycoperdinece being united 

 under the Lycoperdacece. Since the Tulostomece and Lycopcr- 

 dineiz are easily distinguished, Winter's classification seems 

 to better subserve the convenience of the student and is 

 accordingly here, with slight modification, adopted. 



KEY TO THE FAMILIES OF THE GASTEROMYCETES. 



I. Sporocarp tuberous; mostly underground species; peridium concrete 

 with the gleba, indehiscent, cells of the gleba persistent; capillitium 

 wanting. Hymenogastre.e. 



II Sporocarp globose, tuberous, terrestrial ; peridium discrete from the 

 gleba; cells of the gleba subpersistent, with little or no capillitium. 



SCLERODERME.E. 



