300 CLASS ASCOMYCETEAE 



Perithecia and sustaining or enclosing stromata, when present, light-colored 

 or red or blue. Not lichen forming. Order Hypocreales 



Ascocarps dothideal, i.e., consisting of cavities dissolved in a fairly massive in- 

 ternal or external stroma, each such perithecial cavity containing a cluster 

 of parallel or diverging asci separated by the paraphysis-like remains of the 

 stromatic tissue, or these disappearing very early. Ostioles formed by the 

 breaking or dissolving away of the apical portion of the stroma above the 

 perithecial cavity. Order Dothideales 



Ascocarps pseudosphaeriaceous, i.e., consisting of perithecium-like stromata within 

 which the asci are formed in separate monascous cavities, or the intervening 

 tissues dissolve very early so that the asci form a parallel or diverging cluster 

 in a single large cavity. No true paraphyses. Ostioles formed by the breaking 

 or dissolving of the apical portions of the stromata. 



Order Pseudosphaeriales 



Ascocarps external, consisting of usually flattened stromata with a thin outer, 

 colored crust, the basal portion pseudoparenchymatous, with thin-walled 

 cells. The asci are formed in monascous cavities. Mycelium mostly external 

 or subcuticular, often very slightly developed and not easily detected. 



Order Hemisphaeriales 



Ascocarp obviously stromatic with rounded asci single in cavities which are in 

 one or'two layers or irregularly scattered. 



Order Myriangiales (see Chap. 11) 



Because of the large number of genera in the families the following 

 keys are made only for the families. A few of the more important genera 

 are merely mentioned under each family but not keyed out. 



Key to the More Important Families of Order Sphaeriales 



Perithecial walls thin, 



Perithecia light brown, rarely colorless, superficial or sunk in a subiculum, 

 ostiole with papilla or well-developed neck. Paraphyses wanting. 

 Ascospores dark-colored, discharged at maturity. 



Family Melanosporaceae 

 Melanospora, Neurospora, Gelasinospora. 

 Perithecia dark brown, superficial or sunk in a subiculum, rarely partially sunk 

 in the substratum or in a stroma, not conspicuously hairy. Ascospores 

 dark-colored, with slime coat or appendages, paraphyses present, asco- 

 spores discharged through the ostiole. 



Family Fimetariaceae (Sordariaceae) 

 Fimetaria (Sordaria), Schizothecium (Pletirage), Hypocopra, Sporormia. 

 Perithecia dark, hairy all over and with a tuft of periostiolar bristles. Ascospores 

 dark-colored. Paraphyses wanting. Asci dissolving at maturity. 



Family Chaetomiaceae 

 Chaetomium, Ascotricha. 

 Perithecial walls firm and dark. 



Perithecia superficial or sitting in a subiculum, ostiole simple or in a low papilla. 

 Paraphyses mostly present. Ascospores hyaline or colored, one-celled 

 or several-celled. Asci not dissolving at maturity. 



Family Sphaeriaceae 

 Zignoella, Melanomma, Rosellinia. 



