May 26 1923 
Graminicolous Species of Helminthosporium 
685 
constriction; the basal, like the distal end, usually presents a hemi¬ 
spherical contour within which the small dark hilum marking the point 
of attachment may be readily recognized. Germination normally pro¬ 
ceeds by the production of one to three germ tubes from the basal cell, 
at positions approximately midway between hilum and basal segment, 
not usually immediately adjacent to the hilum. (PL 14, Ca, Cc-g.) 
Other modes of germination, as, for example, the production of a germ 
tube from the apical segment (PI. 14, Cb), may be regarded as abnormal 
and usually are attributable to the death of the basal segment as evidenced 
by the concave contour of the cross wall in contact with the adjacent 
living segment. 
HELMINTHOSPORIUM TRISEPTATUM, N. SP. 
In collections of velvet grass (Notholcus lanatus [L.] Nash [ — Holcus 
lanatus L.]) made near Port Washington, Mineola, Douglaston, and other 
localities on the western end of Long Island during the months of July 
and August, 1920, a fungus related to the plants usually referred to the 
genus Helminthosporium was found occurring quite commonly on with¬ 
ered or withering leaves. (PI. 14, E.) As the form is of a t)qDe some¬ 
what different from the majority of the species of Helminthosporium on 
grasses, and does not appear to have been described hitherto, a brief 
account of it may not be out of place. 
The sporophores (PI. 14, Ha-c) are scattered relatively sparsely 
between the long hairs that constitute the abundant pubescense charac¬ 
teristic of velvet grass. They are distinguished not only by being rela¬ 
tively long, but also by the presence of ring-like thickenings of the 
peripheral well immediately below the points of attachment of the suc¬ 
cessive spores. The upper portion of the sporophore may thus present 
a more or less distinctly moniliform contour, wdthin which the lumen 
maintains an approximately uniform diameter. 
Compared to the other species of Helminthosporium discussed in this 
paper, the spores (PI. 14, Fa-f) of the fungus on velvet grass show per¬ 
haps the greatest degree of constancy with regard to morphological 
features. Associated with the dark olivaceous color is a peripheral wall 
not exceeded in thickness by that of any of the related forms described 
in this paper. At the basal end, however, it decreases uniformly in 
thickness toward the hilum, where the curved inner and outer contours 
appeaf to become tangent to each other. This condition is present also 
in other forms as, for example, in Helminthosporium monoceras, where, 
however, the wall is similarly attenuated at the apical end, a difference 
reflected in mode of germination characteristic of the species. For, 
whereas H. monoceras germinates from both ends, in the form under 
consideration only the basal segment normally participates directly in 
the process. (PL 14, Ga-e.) 
The fungus appears to be mainly, if not wholly saprophytic. It is 
referred to the genus Helminthosporium rather than to Brachysporium, 
as in well developed spores (PL 14, Fe) the length is somewhat greater 
in proportion to the diameter than generally appears to be true in fungi 
assigned to the latter genus. The specific name triseptatum is suggested 
because of the number of septa characteristic of typical spores. 
