688 
Journal of Agricultural Research 
Vol. XXIV, No. 8 
(25) and the one found parasitic on Kentucky bluegrass is such as to 
make it appear altogether improbable that Karsten was dealing with 
the form under consideration. Napicladium gramineum described by 
Peck {108) as destructive to Poa trivialis L., is similarly a fungus of much 
smaller dimensions, the i to 3 septate, clavate spores measuring only 10 
to 12 by 30 to 60 /i. In more recent years, BaudyS (9) has reported from 
Bohemia, a new species of Helminthosporium on the living leaves of 
Poa trivialiSy which he named H. poae. Unfortunately, the writer has 
not been able to secure a copy of BaudyiS’ paper and consequently has 
not been able to decide definitely as to any possible identity of H. poae 
Baudy§, either with the species of Napicladium described by Peck, on 
the one hand, or, on the other, with the fungus attacking Kentucky blue- 
grass.^® As Poa pratensis is presumably common in Bohemia, BaudyS' 
failure to record his fungus as developing on this grass would seem to 
have considerable significance in this connection. The species parasitic 
on Kentucky bluegrass is accordingly described as new; and because of 
its widespread occurrence in meagre quantity, the name H. vagans is 
proposed. 
DIAGNOSIS 
Helminthosporium vagans, n. sp. 
Producing well-defined, bluish-black spots 0.5 to 3 mm. wide, i to 8 mm. long, on 
the leaf blades of Poa pratensis L.; on the sheaths the spots less definitely circumscribed 
and near the base of the plant often merging into a generally diffused brownish dis¬ 
coloration. 
Conidiophores emerging from stomata or between epidermal cells of tissues some 
time after death, usually singly or less frequently in pairs; typically sirtiple although 
occasionally branching; dark olivaceous; usually measuring 8 to 10 in diameter and 
50 to 280 M in length; i to 10 septate, the septa occurring at intervals of 15 to 40 /x; 
approximately straight up to point of attachment of first spore 40 to 150 ju from base; 
successive spores produced at apices of moderate or often pronounced geniculations. 
Conidia dark olivaceous when fully mature; cylindrical or slightly tapering toward 
the hemispherical ends; measuring usually 17 to 23 ju in diameter by 25 to 130 n in 
length; i to 10 (usually 5 to 8) septate, the septa not associated with constrictions in 
the peripheral wall; the latter always thick and including the dark hilum within its 
contour. Germinating by the production of 3 to ii germ tubes indiscriminately 
from end and middle segments, a single germ tube usually being produced from several 
or all segments. 
Habitat.—Collected on Poa pratensis at Madison, Wis.; Brooklyn, N. Y.; Blooming¬ 
ton, Ill.; Annapolis, Md.; Washington, D. C.; Hyde Park, Mass.; Meriden, Conn.; and 
Lisbon Falls, Me. 
HELMINTHOSPORIUM RAVENELII CURTIS 
Helminthosporium hoffmanni B. Mss. or H. hoffmanni B. & C. 1857, in Introduction 
to cryptogamic botany, p. 298. 
Helminthosporium tonkinense Karst. & Roum. 1890, in Rev. Mycol. ann. 12, no. 46, 
P- 78- 
Helminthosporium crustaceum P. Hennings 1902, in Hedwigia, Bd. 41, p. 147. 
Although of very little economic importance, Helminthosporium 
raveneliiy owing to its conspicuousness and wide occurrence throughout 
many of the warmer regions of the globe, has become one of the best 
known members of the genus. It was described in 1848 by Curtis (26), 
who noted also its abundant distribution in North and South Carolina. 
This brief account, however, seems to have escaped the attention of 
mycologists generally; for when Berkeley (jj) some years later figured 
Since this text was written, Bandyfi’ paper has become accessible. The Bohemian fungus produces 
spores provided with 2 to 6 cross-walls and measuring 36 to 73 M in length. The foliar .spots occasioned 
by it are described as yellowish with a dark brown margin. In respect to these charateristics, the 
departures from the morphology of the American parasite would appear to preclude any likelihood of 
the two forms being identical. 
