260 



Mycologia 



The fungus sclerotium develops as the bud enlarges and 

 emerges from the covering leaves. The mycelium develops 

 within the bud and also forms a white layer over the outside 

 (Fig. i). On this white layer the conidial stage of the fungus 

 develops. The short and narrow conidiophores form a very 

 dense layer from forty to fifty microns thick over the surface 

 of the sclerotium. The small hyaline conidia develop very 

 abundantly often collecting in mucilaginous drops on the surface. 



Following the conidial stage, the sclerotium continues to in- 

 crease in size, turns black in color, and the exterior mycelial layer 

 increases in thickness. The mature sclerotium (Fig. 3) consists 

 of a mass of small nodules each representing one of the stems 

 of the flower cluster. Sometimes these nodules are more or less 

 separate but generally they are all cemented together in one mass. 

 Frequently on drying, these separate to some extent. The in- 

 terior of the sclerotium is typical of this genus, it being composed 

 of both fungous and host tissues. 



The perithecia of the fungus form in the black outer layer of 

 the mature sclerotium. They are embedded in the tissue with 

 only the ostioles extending slightly above the surface. The ascus 

 has the peculiar bulbous apex found in other species of this genus. 



Very seldom is there any development of the parts of the flower 

 cluster of infected plants, though occasionally a stalk or two will 

 push out of the sclerotium for a short distance and form rudi- 

 mentary spikelets (Fig. 4). Sometimes when this happens, a 

 secondary sclerotium will develop on this branch. 



Specimens of this fungus were sent to the late Professor G. 

 F. Atkinson, who had made considerable study of this genus, and 

 he stated that it was undoubtedly an undescribed species. The 

 technical description of the fungus follows. 



Balansia cyperi sp. nov. 



Sclerotium made up of fungous and host elements, developing 

 in the flower cluster ; sometimes one for each branch of the clus- 

 ter but generally a large, compound, nodose sclerotium in place 

 of the whole flower cluster; slightly stipitate or sessile, 1-3 cm. 

 in diameter, white to greyish in .color during early development, 

 but black, hard and papillate at maturity. Conidia developing on 



