256 CLASS ASCOMYCETEAE 



Canals not opening to surface, fertile their whole length. Choiromyces 

 Asci not in a palisade but irregularly arranged. 



Ascocarp containing empty canals or chambers or hypha-filled "venae ex- 

 ternae" (i.e., canals reaching toward the surface but filled with 

 hyphae). 

 Cavities empty, not opening to surface. Balsamia 



Cavities mostly hypha-filled, opening to surface. 



Ascospores smooth. Pseudohalsamia 



Ascospores variously sculptured. 



Venae externae with parallel venae internae. Tuber 



No venae internae. 

 Asci 8-spored. Hydnobolites 



Asci 1- to 4-spored. Delastreopsis 



Interior of ascocarp divided by sterile veins into nest-like fruiting areas; no 

 venae externae or empty canals or chambers. 

 Ascospores smooth, very large. Picoa 



Ascospores sculptured. 



Asci 8-spored. Terfezia 



Asci 2- to 4-spored. Delastria 



fThe genera Hydnobolites, Delastreopsis, Picoa, Terfezia, and Delastria are placed 

 in some works in Family Terfeziaceae, Order Aspergillales, Fischer, 

 1896b). 



Key to the More Important Genera of Order Hysteriales 



{Modified from von Hohnel, 1918) 



Ascocarp superficial in subiculum or becoming superficial by emerging from the 

 substratum, elongated or linear, not strongly compressed nor with strongly 

 developed keel. 

 With brown subiculum, ascospores 2-celled, hyaline. Glonium 



Without subiculum. 



Ascospores 2-celled, hyaline. Psiloglonium 



Ascospores with 2 or more cross septa, hyaline. Gloniella 



Ascospores similar but colored. Hysterium 



Ascospores muriform, hyaline. Gloniopsis 



Ascospores muriform, colored. Hysterographium 



Ascocarp entirely superficial, strongly compressed laterally and with a well- 

 developed keel, mussel-shaped. 

 Ascospores brown, 2-celled. Bulliardiella 



Ascospores brown, with 2 or more cross septa. Mytilidion 



Ascospores brown, large, fusiform, with many cross septa. Ostreion 

 Ascospores hyaline, thread-formed. Lophium 



The genera with permanently immersed ascocarps, are to be found in the Phacid- 

 iaceae; Lophodermium, Hypoderma, etc. 



Key to the Genera of Order Taphrinales 



Asci forming an indeterminate hymenium, on a hyphal hypothecium several 

 cells thick on the surface of the woody substratum. 



Family Ascocorticiaceae 

 Only one genus. Ascocorticium 



