Ustilago Zesd (CORN SMUT)* 



A. Classification: 

 Division I. Thallophyta. 



Subdivision B. Fungi. 



Class V. Basidiomycetes (Basidium fungi). 

 Order. Ustilaginales. 

 Family. Ustilaginaceae. 

 Genus. Ustilago. 

 Species. Zees (Beckm.) Ung. 



B. Habitat: 



i. Upon what part or parts of the corn plant is the 

 smut found? Does it differ in this respect from 

 smut on wheat, oat, and other common grains? 

 If so, how? 



C. Naked-eye Characters: 



1. Describe the appearance of the host as affected by 

 the parasite. Cut into both young and old smutted 

 areas and describe the appearance of the infected 

 regions. 



2. Draw, to show the part of the host plant infected, 

 and the degree of enlargement of the smutted tis- 

 sues as compared with the normal. 



D. Microscopic Characters: 



1. With scalpel or forceps remove some of the spores 

 (often called "chlamydospores") from a smut-boil, 

 mount, and study with both low and high powers. 



2. Draw, to show the shape and surface markings of 

 the spores. 



3. If the spores are of the proper degree of maturity, 

 they can be germinated on the surface of water, 



1 See footnote, p. 135. 



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