May 26, X923 
' Graminicolous Species of Helminthosporium 
689 
the fungus in his '‘Introduction to Cryptogamic Botany/’ he designated 
it as H. hoffmanni B. and C., without any further comment beyond the 
words, ‘ ‘ From specimens on Sporoholus indicus. Sent by Rev. M. A. Curtis. ’ ^ 
Later in a brief descriptive discussion in the “Notices of North American 
Fungi” Berkeley (12) cited H. hoffmanni B. Mss. as a synonym of H. rave- 
nelii, which binomial he correctly credited to Curtis alone. Neverthe¬ 
less, as the publication of the original specific diagnosis in an American 
journal has apparently remained relatively unknown both in this country 
and abroad, the name frequently has been improperly attributed to the 
joint authorship of Berkeley and Curtis. 
The earliest collections of the fungus made by Curtis were from North 
and South Carolina. Material from the rest of the South Atlantic States 
and from the Gulf States, Georgia, Florida, Alabama, Mississippi, Louisi¬ 
ana, and Texas, as well as from Mexico and China, is included in numerous 
collections in the herbarium of the Office of Pathological Collections. 
Specimens of the parasite collected in Costa Rica were distributed by 
Sydow.“ Kabdt and Bubdk^^ distributed material from Uraguay and 
Theissen material from Brazil. The fungus, moreover, has been 
reported from Cuba by Berkeley (72), from Bermuda by Seaver 
from New Zealand by Kirk (7^), from New South Wales by Cobb {22)^ 
and from the Philippines by Hennings (60), Baker (5), H. and P. Sydow 
{148), and Yates {160). There is good reason to believe that its dis¬ 
tribution is practically coterminous with that of its host, Sporoholus 
indicus R. Whether other grasses also are subject to attack is not 
altogether certain, although Yates (160) records the occurrence of the 
fungus on the inflorescence of Panicum auritum in the Philippines, and 
Fimbristylis is given as the host on the covers of Theissen’s Brazilian 
specimens. More information concerning the identity of the host 
material on which these records are based would be desirable. It may 
be stated that Sporoholus angustus Buckl. and 5 . elongatus R., sometimes 
mentioned as hosts, are listed in the Index Kewensis as synonyms of 
5 . indicus, 
Helminthosporium ravenelii attacks the inflorescence of Sporoholus 
indicus in our southeastern states with such regularity that, as has been 
observed by Curtis (^6), Jennings (67), and others, it is often quite 
difficult to obtain a specimen of this species of grass entirely free from 
the fungus. Indeed, there is reason to believe that the distinctive color 
and texture of the diseased panicle is popularly regarded as common¬ 
place attributes of the host, as is evidenced by the common names applied 
to it in the United States, namely, “black seed grass” {26) and “smut 
grass” (47). These terms are fairly accurately descriptive of the later 
stages, when the infected inflorescence has a black crusted appearance; 
but much less accurately descriptive of the earlier stages (PI. 16, A) 
when the fungus is present as a velvety or spongy layer of a brownish 
olive color, that only later becomes increasingly dark. 
This velvety layer, under the microscope, is seen to consist of crowded 
sporophores (PI. 16, B) arising from a mat of interwoven colorless 
mycelial hyphae that occupy the superficial layers of the affected floral 
parts. Unlike the homologous structures of nearly all congeneric forms 
parasitic on grasses, the sporophores of H. ravenelii exhibit a constant 
Sydow, H. fungi bxoyica exsiccati. Helmmihosporkim ravenelii B. and C. No. 442. 1912. 
“ Xab At et BubAk. fungi imperfecti exsiccati. No. 540. Helminthosporium ravenelii Curt, et Burk. 
1907. 
Theissen, F. decades fungorum brashiensium. No. 277. 1905. 
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