Feb. s, 1917 
Leafspot-Rot of Pond Lilies 
225 
conidial inoculations. Observation after nine days showed typical spots, some of 
which were 40 mm. in diameter, and so far as could be determined infection had 
occurred at all points of inoculation. The yellowish halo around the infection areas 
was prominent in each case. 
PARASITISM OF THE FUNGUS 
Through the inoculation tests above outlined the parasitism oi this 
fungus to leaves of pond lily (Nymphaea spp.) is clearly established. 
Inoculations were made during three years with six different isolations 
obtained from four localities on leaves of nine species of pond lily. In 
one experiment where cultures 45 days old were used, seven only out of 
nine inoculated leaves developed the disease. However, all other in¬ 
oculations, including several leaves inoculated from cultures 2 months 
old, were successful. Thus, out of a total of 135 leaves inoculated on the 
upper surface during three seasons, 133 leaves developed the disease in 
many places. In fact, in nearly all cases, so far as could be determined, 
the diseased spots appeared wherever the conidia were placed. 
Inoculations on the lower epidermis of pond-lily leaves were partially 
successful. These infections when they occurred were slower in start¬ 
ing, but once started the progress of the disease was apparently as rapid 
as with inoculations from the upper surface. 
In the one inoculation test made with this fungus on leaves of Egyp¬ 
tian lotus (Nelumbium speciosum) no infection resulted. 
CULTURAL CHARACTERS OF THE FUNGUS 
The gross characters of the fungus as grown upon several of the com¬ 
mon culture media are as follows: Color descriptions are according to 
Ridgway. 1 
On beef-agar slants a smooth, pale, vinaceous fawn to vinaceous buff, feltlike mat of 
mycelium soon develops on the surface of the medium. After two to three weeks no 
further change takes place except a gradual drying of the agar. No sclerotia have 
been observed, but branching hyphae with swollen cells are frequent, and somewhat 
atypical conidia are sparingly developed. 
In beef bouillon in test tubes a water-tight felt is formed at the surface of the liquid, 
the latter remaining clear after several weeks. This mycelial mat is at first whitish 
but later approaches a pale vinaceous fawn to vinaceous buff color. 
On com-meal-agar slants the growth is at first whitish with scant aerial mycelium. 
In four to five days conidia begin to develop in the central portion of the colonies, giv¬ 
ing a velvety appearance to the surface. In color the sporulating surface is Dresden 
brown to mummy-brown. After two to three weeks the dark, velvety sporulating 
portion nearly to quite covers the surface of the slant and the medium to the depth 
of several millimeters gradually assumes a light purplish-vinaceous to purplish-vina- 
ceous cast which grades off into the pearl-gray of the agar. From this diffusion of the 
pigment into the medium it is clearly shown to be a water-soluble substance. Black, 
roundish sclerotia consisting of a solid mass of fungus cells often develop in old corn- 
meal-agar cultures (PI. 67, C-E). 
1 Ridgway, Robert. Op. cit. 
