CHAPTER XVI 

 HYPOCREALES 



The Hypocreales are generally denned as Pyrenomycetes with a soft 

 (not hard and carbonaceous and hence not brittle), brightly colored 

 (white, yellow, red, violet or light brown) perithecial wall. Where 

 systematic relationships are firmly established, occasionally we include 

 dark-colored or hard-walled forms, such as Ophiodotis, Entonaema and 

 Xylocrea, which according to the definition would belong to the Dothide- 

 ales or Sphaeriales. 



There are so many Hypocreales that it seems impossible to give 

 a satisfactory systematic classification. Lindau (1897) and Seaver 

 (1910) use as the fundamental principle, the behavior of the perithecia, 

 whether they are solitary or united in slightly or highly differentiated 

 stromata; they realize, however, that the consistent following of this 

 principle separates parts of the same natural genus among entirely 

 different families. In order to lessen this difficulty, which would be very 

 serious in the present work, we have used the septation of ascospores 

 as the only principle of division, as advocated by Saccardo in the 

 Sylloge Fungorum and by Moller (1901). Thus we have divided the 

 genera selected for discussion here into three groups : the first contains the 

 Amerosporeae (ascospores unicellular) ; the second includes the Didymos- 

 porae (ascospores bicellular), the Phragmosporae (ascospores tri- and 

 multicellular) and the Dictyosporae (ascospores reticulately septate); 

 the third contains the Scolecosporae (ascospores filamentous, unicellu- 

 lar at first, becoming multicellular). 



It is obvious that this classification is entirely artificial; it has the 

 advantage, however, that there is rarely any doubt as to where one 

 should seek a genus. Further, it seems that the Scolecosporae, at least, 

 form a more natural group because of the behaviour of their ascospores; 

 their asci are always long, slender and fine and, as far as known, always 

 have a characteristic cap with a thread-like canal. It is possible that 

 this peculiar structure of the ascus is older and more important for a 

 natural systematic classification than the morphology of the spores. 



The Amerosporae may be divided into three stages, the first, in which 

 the perithecia generally stand singly on the substrate, the second, in 

 which they are united in undifferentiated cushions and the third, in 

 which these pulvinate stromata develop into specially formed fructifica- 

 tions. Of the first group, we will cite here four genera, Melanospora, 



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