THE FUNGI WHICH CAUSE BLANT DISEASE 



235 



Over seventy species, several of which are parasitic but none of 

 importance in America. 



C. laburni Pers. is on branches of Cytisus; 



C. sorbi Karst on Sorbus twigs; 



C. pityophila (Kze.) d Not. on various conifer twigs; 



C. berberidis (Pers.) Gray on Berberis; 



C. elongata (Fr.) Grev. on Robinia; 



C. piceae Brothwick, on Picea. 



Mycosphaerellacese (p. 223) 



Perithecia mostly subepidermal, rarely subcuticular, finally 

 more or less erumpent or even superficial, membranous or leathery, 



Fig. 169.— 

 Gibbera vac- 

 cinii. An 

 ascus. After 

 Winter. 



Fig. 170. — Cucurbitaria berberidis. 0, 

 habit sketch ; H, ascus. After Lindau 

 and Winter. 



fragile; asci fasciculate, 8-spored; spores variable, septate, rarely 

 muriform, hyaline to dark-brown; paraphyses none. 



This family of over seven hundred species contains many sap- 

 rophytes and several very important parasites. 



Key to Genera of Mycosphaerellace» 



Spores 1 to 2-celled 

 Spores hyaline or green 

 Spores 1-celled or not clearly 2-celled 

 Perithecia very small, on a basal 

 growth of thick branched hyphse 



1. Ascospora, p. 236. 



