Xcbraska I'orcst l<un<ji. II 



97 



Ramularia ccltidis E. & K. 



Discolored spots bearing the fertile hyphae on both sides 

 of the leaf, small (1-2 mm.) round, with a thin, white center and 

 a brown margin limited by a well defined, narrow, slightly raised 

 line. Hyphae very short, entire, hyaline, in little tufts which 

 appear like fine powder sprinkled over the spots. Spores long, 

 nearly cylindrical, hyaline, slightly curved or straight, 1-3 septate, 

 25-50x2 microns. On living leaves of Celtis occidentals, 



Cylindrium 



Fertile hyphae very short, nearly obsolete, hardly differing 

 from the spores. Spores in chains, elongate-cylindrical, obtuse 

 at both ends, hyaline or bright colored. The very fine clusters 

 of hyphae and spores give a powdery appearance to the dis- 

 colored fruiting spots. 



Cylindrium clongatnm Bon. 



Tiny clusters of fruiting hyphae white and loose. Chains 

 of spores long, flexuous, cylindrical-fusoid, 15-18 microns long, 

 2 microns wide, hyaline or whitish, with an oil drop at each end. 

 Hyphae very short or obsolete. On the fruits and leaves of 

 Quercus. 



Demafiaceae: 



Hyphae dark or black, cobwebby, loose, usually rigid. 

 Spores typically dark but sometimes the hyphae are dark and the 



spores clear, or the spores dark and 

 the hyphae clear. This family is 

 more or less parallel with the 

 Muccdinaceac and there are many 

 intermediate forms. 



Cercospora 



Fertile hyphae well developed, 

 smooth or somewhat roughened 

 above, simple or branched, dark, 

 often in tiny congested tufts scat- 

 tered over definitely limited, dis- 

 colored areas of the leaf. Spore? 

 long, of various shapes, vermicular, 

 Fig. 24. Cercospora on often curved, septate, dark, olivace- 

 Gymnocladus. a. Cluster of ous, rarely nearly hyaline. See 

 spores, b. Two spores en- fig. 24. This genus is composed of 

 larged. All highly magnified, hundreds of described species that 



