ECONOMIC IMPORTANCE OF FUNGI 



293 



Ireland, in 1846-47. (The disease known as "little pota- 

 toes" {Rhizoctonia) and by various other names (Fig. 213), 

 is caused by one of the Basidiomycetes.) 



283. Ascomycetes. — Among diseases caused by various 

 species of sac-fungi are the following: 



Fig. 215. — Ergot {Claviceps purpurea). Sclerotia on wild rye {Elymus 

 virginicus), at left; marsh grass {Spartina sp.), middle; cultivated rye 

 {Secale cereale), at right. 



1. Peach leaf-curl, plum pockets, and "witches brooms" 

 (Fig. 214). 



2. Brown rot of peach and plum. The damage caused 

 by this disease in the state of Georgia alone, in 1900, 

 amounted to nearly $700,000. 



