334 CLASS ASCOMYCETEAE 



Elsinoe consists of a good many species of plant parasites which pro- 

 duce their stromata under or within the epidermis. By the rupture of the 

 latter the stroma containing the scattered asci becomes exposed. Unlike 

 Myriangium, in which no conidia have been observed, there are produced 

 acervuli or sporodochia bearing unicellular, hyaline conidia, of the form 

 genus Sphaceloma. E. veneta (Speg.) Jenkins is the cause of anthracnose 

 of Rubus, E. ampelina (de Bary) Shear of anthracnose of Vitis, E. piri 

 (Wor.) Jenkins of anthracnose of pear (Pirus) and apple {Malus). Other 

 species of Elsinoe cause serious diseases of species of Citrus, Canavalia, 

 Phaseolus, etc. The ascospores are in most cases septate transversely but 

 in a few cases longitudinal septa also are present. Including those so far 

 known only in the characteristic Sphaceloma stage about 175 species of 

 Elsinoe are recognized in the whole world (Jenkins, 1947) of which above 

 40 occur in the continental United States and the island possessions, 

 Puerto Rico, Hawaii, and Guam. The diseases produced are in the later 

 literature called "spot anthracnoses." Other genera are reported mainly 

 from the tropics, some parasitic in plants, some upon insects. (Fig. 108 

 D, E.) 



The relationship of this family to other Aspergillales or its justification 

 as a separate but closely related order is uncertain. In some particulars it 

 reminds one of the Trichocomaceae, and more distantly of the Elapho- 

 mycetaceae. Raciborski (1909) has suggested the possible relationship of 

 the Atichiaceae to the Myriangiaceae, but the structure and development 

 of the ascocarp appears to be too fundamentally different in the two 

 families in so far as the meager information is available on these points in 

 the former family. The possible relationship of the Myriangiaceae to the 

 Pseudosphaeriales is discussed in Chapter 17. 



Order Saccharomycetales. This order represents, in the opinion of the 

 author, the ultimate degree of simplification in the Class Ascomyceteae. 

 On the other hand it must be noted that by many eminent mycologists, 

 such as de Bary (1884), Brefeld (1889), Gaumann (1926), Dangeard 

 (1907), Atkinson (1915), and others, the members of this order are looked 

 upon as primitively simple, representing almost the first steps in the evo- 

 lution of the Ascomyceteae from the Phycomyceteae. To agree with this 

 theory the arrangement of the orders of this class should be the reverse of 

 that used in this book, placing the Saccharomycetales first and the 

 Pezizales and their allies last. 



The fungi making up this order are filamentous or unicellular (Yeasts). 

 In the latter case the cells often remain attached until several cell divi- 

 sions have occurred forming an irregular mass but usually not a cylin- 

 drical hypha. The fundamental common character of all the members of 

 the order is the production of single asci, usually as the result of a sexual 

 process but sometimes parthenogenetically, instead of a cluster of asci 



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