May 26 , 1933 
Graminicolous Species of Helminthosporium 
731 
DIAGNOSIS 
Helminthosporium cyclops, n. sp. 
Occurring on the leaves of Danthonia spicata (D.) Beauv. on which it causes small 
dark-brown spots not usually in abundance. 
Conidiophores, olivaceous, usually 3 to 7 septate, the septa occurring at intervals 
of 18 to 50 m; measuring 7 to 8 ^ in diameter by 100 to 250 ^ in length; producing the 
first spore from 80 to 160 /a from the base, and successive spores at the apices of moder¬ 
ately pronounced geniculations. 
Conidia, dark olivaceous except in restricted subhyaline regions at apex and base; 
straight or rarely slightly curved, cylindrical or tapering gently toward ^e bluntly 
rounded ends, the shorter ones often ellipsoid; measuring usually 12 to 17 in diameter 
by 45 to no /i in length; 4 to 12 septate, the septa not usually associated with con¬ 
strictions in the peripheral wall; the latter thick except in the subhyaline regions 
from which the two polar germ tubes are produced, one at the apex, and the other 
immediately surrounding the unusually large and conspicuous hilum included within 
the basal contour. 
On agar media containing abundant organic food material, producing numbers of 
superficial subspherical sclerotia resembling immature perithecia of congeneric forms. 
On agar media containing little organic food material, developing imbedded sclerotia, 
discrete fructifications and compound fructifications. Conidiphores of discrete 
fructifications arising from more delicate subhyaline vegetative hyphae often becom¬ 
ing branched as a result of individual spores being produced into sporophoric pro¬ 
longations and occasionally continuing growth by budding in a manner analogous to 
the proliferation of spores. Conidia like those produced in nature but usually snorter, 
ellipsoidal, rarely exceeding 18 fx in diameter and 60 in length. 
Compound fructifications consisting of a threadlike axis 0.3 to 0.5 mm. in diameter, 
10 mm. or more in length, composed of hard, white pseudoparenchyma with black 
mottled surface, and bearing numerous radially oriented sporophores above the some¬ 
what expanded sterile basal portion. 
Habitat. —Collected near Norwood, Mass., November 7, 1920; and Disbon Falls, 
Me., July 20, 1921. 
LITERATURE CITED 
(1) Anderson, J. P. 
[1920]. SOME ALASKA FUNGI. In Ptoc. lowa Acad. Sci. 1920, v. 27, p. 99-108. 
(2) Atanasoff, D. 
1919. A NOVEL method of ascosporE DISCHARGE. In Mycologia, V. II, p. 
125-128, 3 fig. 
(3) -Johnson, A. G. 
1920. TREATMENT OF CEREAL SEEDS BY DRY HEAT. In JouT Agr. Research, v. 
18, p. 379-390, pi. 48-49. Literature cited, p. 388-390. 
(4) Atkinson, G. F. 
1897. SOME FUNGI FROM ALABAMA... Bul. Comell Univ. (Sci.), V. 3, no. I, 
50 p. Bibliography, p. 2. 
(5) Baker, C. F. 
1914. THE LOWER FUNGI OF THE PHILIPPINE ISLANDS. In Leaflets Philippine 
Bot., V. 6, p. 2065-2190. 
(6) BakkE, a. L. 
1912. THE LATE BLIGHT OF BARLEY (HELMINTHOSPORIUM TERES SACC.). In 
Proc. Iowa Acad. Sci., v. 19, p. 93-102, pi. 1-3. Bibliography, p. loi. 
(7) - 
1918. LONGEVITY OF HELMINTHOSPORIUM TERES. (Abstract.) In Phytopath¬ 
ology, V. 8, p. 80. 
(8 ) Bassi, E. 
1921. UNA FORTE INFEZIONE DI **HELMINT 0 SP 0 RIUM’* O MARCIUME DEI NODI 
DEL GRANO. In Italia Agr., ann. 58, p. 298-301, 2 fig. 
(9) BaudyS, Eduard. 
1915-16. EiN beitrag zur kenntnis der mikromyceten in b6hmen. In 
Lotos, Bd. 63, p. 103-112; Bd. 64, p. 11-29, 42-64> 80-85, illus. 
(10) Beckwith, T. D. 
1911. ROOT AND CULM INFECTIONS OF WHEAT BY SOIL FUNGI IN NORTH DAKOTA. 
In Phytopathology, v. i, p. 169-176. Bibliographical footnotes. 
(11) Berkeley, m. j. 
1857. introduction TO CRYPTOGAMic botany... viii, 604 p., 127 fig. London. 
(12) 
1875. NOTICES OF NORTH AMERICAN FUNGI. In Grevillea, V. 3, p. 49 - 64 » 97-112 . 
