GROUP IV. BASIDIO-USTlIvAGINB^. Smuts. 



Spores minute, sooty, developed either on delicate threads 

 (hyphse) or in compacted cells, arising first from a sort of 

 semigelatinous grumous stroma. Parasitic ; attacking flowers, 

 leaves, and stalks of herbaceous plants. The genera included, 

 indigenous in our Valley, are as follows : 



Phacelotheca. — Developed in the ovary of the Phenero- 



gamic genus or Polygonum. 

 Kntyloma. — Spots pale rusty brown, enclosed in a deformed 



tissue host. 

 TiLLETiA. — Spots pulverulent at maturit}' , black. 

 UsTiLAGO. — Hymenium deeply seattd in the tissue of the 

 plant in the form of hyphae, ultimately breaking 

 in a powdery mass. 



Genus I. PHACBI.OTHBCA. 



Spores developed in a receptacle formed by the fungus in the 

 ovary ; columella present. 



P. polygoni. 



Produced in the ovary of the flowers of Polygonum 

 amphibium. 



Easily identified by walking through a bed of the host, for 

 it is nothing but a mass of smut, the red spikes are nearly all 

 changed to a sooty mass. 



Koch's Island. 



Genus II. BNTYlvOMA. 



Spots pustule-like, pale or rusty brown, parasitic on leaves 



and stems. 



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