May a6 ,1993 
Graminicolous Species of Helminthosporium 
693 
may be invaded in the same way, often stunting their development and 
softening the discolored cortical tissue. Undoubtedly, quite similar 
pathological processes take place when the seedlings are planted in soil. 
The effect of such early infection, moreover, then becomes apparent in 
the development of the seedling, for, in addition to the lesions on seed, 
sheath, and root system, conspicuous dark brown spots may occur on 
the first few leaves, thus giving rise to the thoroughly diseased condition 
described and illustrated by Atanasofif and Johnson. 
It may be mentioned in this connection that a discoloration of barley 
seed evidently quite similar to that frequently observed in the United 
States was noted by a number of European writers. Zobl (j6j, 164), 
in 1892, published some papers on '‘brown-pointed” (braunspitzige) 
barley, in which the discoloration is described as being most intense at 
the base of the seed and decreasing toward the apex. Although various 
fungi belonging to the genera Sporodesmium, Cladosporium, Helmintho¬ 
sporium, and Dematium were found associated with discolored seeds, 
Zobl attributed the brown-point condition primarily to Cladosporium 
herbarum, Puchner (iij), in some studies on “black-pointed” {schwarz- 
spitzige) barley seed, found that these germinated abnormally, often 
producing plants the leaves of which bore brown spots. However, when 
barley seed similarly affected was treated with copper sulphate prelimi¬ 
nary to sowing the foliar lesions failed to appear in the seedling, although 
during the later stages in development the foliage and inflorescence of the 
originally healthy plant were as subject to attack as those of a diseased 
specimen. Ravn {113) found a fairly close correlation existing between 
the prevalence of net-blotch and “brown point” {brune Spidsers) in the 
seed. Without regarding a causal relation as firmly established, he 
nevertheless appears to have been inclined to see in Helminthosporium 
teres the most probable cause of seed discoloration. 
While the evidence adduced by Ravn would appear altogether suffi¬ 
cient to justify his view, as far as conditions in Denmark at the time his 
investigations were carried on were concerned, the fact remains that in 
our North Central States H, teres is not generally associated with black- 
pointed barley seeds. On the other hand, as has been mentioned before, 
the association of H. sativum with this condition appears unusually 
constant. For example, when discolored barley seeds from stock grown 
in Wisconsin are plated on agar, after proper surface sterilization, only 
a very small proportion of seeds will fail to give rise to mycelia and 
conidiophores of the parasite causing spot-blotch. Presumably H. sati¬ 
vum is of less frequent occurrence on barley in Europe than in the United 
States. That it is more common than the absence of references from 
European literature might lead one to infer is suggested, for example, 
by Massee’s (90) account of H. gramineum. The ambiguity with regard 
to the host range of the fungus, and the longevity, color, and size of the 
conidia, fortunately is explained by figures of these bodies (fig. 132-6), 
which show beyond any doubt that this author was dealing not with the 
stripe fungus but with the parasite causing spotblotch. In Eindfors* 
(84) description of H, acrothecioides the existence of a species of Helmin¬ 
thosporium on barley other than H. gramineum and H, teres eventually 
was recorded, but its relation to pathological lesions in the growing 
plants of either barley or of wheat or rye has apparently not yet been 
recognized. 
