262 
Journal of Mycology 
[Vol. 11 
of the crowded perithecia more or less confluent in an irregular 
manner giving a tuberculose, rugulose or convolute appearance to 
the stroma and more prominent than in D. atramentosa, otherwise 
as in D. atramentosa. On Aristida purpurascens, Auburn, Ala¬ 
bama, collected by B. M. Duggar. On Aristida dichotoma, Au¬ 
burn, Alabama, C. L. Newman. On grass which resembles Aris¬ 
tida, at Cocoanut Grove, Florida, Dr. Thaxter collected specimens 
which probably belong to this species, but the perithecia are old 
and sterile in the specimens which I have seen. 
The simple agreement in character of the asci and spores of 
these species cannot be taken as of specific identity where there 
are other characters sufficiently distinct, for there is no appreci¬ 
able difference between the asci and spores of Epichloe typhina 
and those of Dothichloe atramentosa, and in several species of 
Cordyceps they are very similar. 
While I have found the perithecia bearing stroma only on 
the stems, the leaves of affected plants often show a very thin 
black sterile stroma. Whether this sterile stroma on the leaves is 
formed by the same fungus or not I cannot say. It would seem 
that it should bear perithecia if it is specifically identical with 
Dothichloe atramentosa. But since the stroma only fruits on the 
stems (provided the sterile stroma on the leaves belongs to the 
same fungus) this would be another indication of its being a 
distinct species. 
ECONOMIC IMPORTANCE OF THE SPECIES. 
Aside from the very interesting feature in the morphology of 
the species of these two genera, and the interesting and intri¬ 
cate history of their synonymy, they are of special interest in rela¬ 
tion to their hosts because of their possible economic importance. 
So far as we knew they are strictly parasites. The species of the 
genera at present known are intrinsically parasites of the grasses, 
and all the species with which I am at present familiar in the 
United States attack living grasses. Because of the great import¬ 
ance of the grasses for pasturage and forage any fungus which is 
capable of causing disease or injury to members of this order at 
once becomes of considerable economic importance, even though 
at present the percentage of injury which they cause is small. We 
do not know at what moment a change may occur which may 
favor the more rapid multiplication of the parasite and the sus¬ 
ceptibility of the host, as well as the spread of the parasite to some 
of the grasses which are now of greater economic importance 
than those which at present constitute the hosts of the parasite. 
This change to other hosts could very well take place by the evo¬ 
lution of some biologic form especially organized to successfully 
overcome the new host. The primary attack could be made 
through a vulnerable point due to physiological conditions of the 
