512 FUNGI BIPKRFECTI. 



was variable, and the terminal cells, although lighter than the 

 median, were not quite hyaline. The terminal cell bore several 

 very long bristles. 



C. ulmicolum E. et K. On living leaves of Ulmus fnlva in 

 America. 



Helminthosporium. 



Conidia brown, cylindrical or spindle-shaped, and pluricelkdar. 

 Mycelium well-developed and brownish. 



" Distinguished from Cladosporium by the conidia being more 

 than one-septate at maturity " (Massee). 



Helminthosporium gramineum (Piabenh.)^ This causes a 

 disease on barley, both in Europe and the United States ; as yet, 

 however, it is not very common. It attacks generally the lower 

 leaves, producing long, narrow, dark-brown spots with yellow 

 margins. The leaves so attacked gradually wither, but do not 

 prejudice the yield of grain seriously. On the spots are 

 developed the black septate conidiophores, each with a large 

 black conidium with from two to eight cross-septa. 



H. turcicum Pass, causes long spots on the leaves of Zea mais 

 both in Italy and America. The spots are yellow with indistinct 

 dark margins, and from them arise patches of grey septate 

 conidiophores. The conidia resemble those of the species last 

 described, so that some authorities regard the two forms as one. 

 Briosi and Cavara describe the mycelium as consisting of 

 branched septate hyphae, the cells of which frequently become 

 irregularly swollen. The young Indian corn leaves are killed, 

 and the crop may, in consequence, be seriously injured. 



H. teres Sacc. This is a form of H. gramineum which 

 Briosi and Cavara distinguish as occurring on oats. Infection 

 takes place at the apex of the leaves, and the mycelium spreads 

 through the parenchyma causing elongated dry spots, so that 

 the leaf ultimately dries up and dies. The conidiophores are 

 developed singly, not in tufts, and the conidia are smaller than 

 those of H. gramineum. The conidia are greenish, thick-walled, 

 plurieelhdar, and produced terminally. 



H. gracile (Wallr.) causes long marginate spots on the leaves 

 of Iri>> gennanica. 



1 Eriksson, i5oton. Centralblatt, xxix., ISS7. Kirchner, ZeiLschrift /. Pflanzcn- 

 krankheiten, i., 1891, p. 24. 



