682 
Journal of Agricultural Research 
Vol. XXIV. No. 8 
DIAGNOSIS 
Helminthosporium siccans, n. sp. 
Occurring on Lolium multiflorum Dam. (type) and L. perenne L., on which hosts it 
causes a moderately destructive disease of the foliage, producing typically numerous 
dark brown longitudinally elongated spots, usually measuring o.i to 0.3 mm. in width 
by 0.2 to I. o mm. in length that by coalescing often appear as discolored areas several 
times larger. Affected leaves later dying, tiie withering beginning at the tip of the 
blade and eventually involving the sheath wholly or in part. 
Conidiophores olivaceous, emerging usually singly, less frequently in pairs, and 
rarely in groups of three from stomata or more especially from between epidermal cells 
on the vascular ridges; measuring 7 to 9 ju in diameter by 50 to 300 n in length; i to 9 
septate, the septa inserted at intervals of 15 to 90 /x; producing &st conidium at a dis¬ 
tance of 50 to 250 /X from base; points of attachment of successive conidia at angles of 
geniculate irregularities occurring at intervals of 5 to 30 m- 
Conidia subhyaline or light fuliginous when newly proliferated, later becoming yel¬ 
low, brownish, or brownish olivaceous, never dark olivaceous like Helminthosporium 
sativum; when fully mature provided with a moderately thick peripheral wall; typi¬ 
cally straight or slightly cu^ed; measuring usually 14 to 20/x in diameter by 35 to 130 /x 
in length; usually subcylindrical, or tapering slightly or more markedly toward 
apex, the distal segment often not exceeding 10 /x in diameter, or rarely greater in diam¬ 
eter at the distal end than at the base. Apical and basal ends abruptly rounded off, 
the contours at the ends being approximately hemispherical. Hilum moderately con¬ 
spicuous included within contours of peripheral wall. Germinating by the production 
of germ tubes from intermediate as well as end segments, the basal and distal segments 
both usually participating in the process by the proliferation of i or 2 lateral or ob¬ 
lique germ tubes. Of the intermediate segments one, several, or all may produce one 
or rarely two lateral germ tubes. Under natural conditions germination by the pro¬ 
duction of one or less frequently two sporophoric processes, each bearing usually a 
single conidium, is not uncommon. 
Habitat. —Collected in May and June near Annapolis, Md.; Baltimore, Md. ; Rock¬ 
ville, Md.; Kensington, Md.; Washington, D. C.; Arlington, Va.; Mount Vernon,Va. 
HELMINTHOSPORIUM STBNACRUM, N. SP. 
On specimens of Agrostis stolonifera L. collected at various times in 
September, October, and early November, 1920, in southwestern Connec¬ 
ticut, especially in the vicinity of Stamford and Norwalk, J:he writer found 
a well characterized species of Helminthosporium occurring with some 
regularity. The fructifications were found on dry withered leaves that 
formed a considerable proportion of the foliage. Owing to the relatively 
small size of the foliar organs concerned, and the absence of any pro¬ 
nounced discoloration, it was not possible to determine definitely whether 
the dying of the leaves was due to the presence of the fungus or to 
other causes. In general, the distribution of the conidiophores on the 
dead tissues suggested a course of events somewhat similar to that exem¬ 
plified by the parasitism of H, turcicum in ordinary seasons—development 
of the fungus on leaves already reduced in vitality as a result of normal 
maturation, followed by the production of fructifications some time after 
their death. 
The sporophores distributed rather sparsely over the surface of the 
withered leaves are moderately large structures of the same general type 
as those of Helminthosporium teres, although usually more abundantly 
septate and less frequently occurring in groups. (PI. 13, Ca-d.) In 
width, color, character of peripheral membrane, general shape, and mode 
of germination, the spores show some similarity to those of H, gramineum, 
H. teres, and H. avenae. (PI. 13, Aa-r, Ba-c.) In length, however, they 
are decidedly superior to the spores of H, gramineum, and in an approxi¬ 
mately equal degree inferior to those of the other two species. While 
in newly proliferated spores the peripheral wall may exhibit slight 
constrictions at the septa, the contour of fully mature spores usually is 
