Nov., 1909.] 
Potato Agar. 
!3 
THE LABRADOR TEA IN OHIO. 
Otto E. Jennings. 
In the Ohio Naturalist for December, 1908, Professor J. H. 
Schaffner presents a list of “Plants on the Ohio State List not 
Represented in the State Herbarium” and proposes to strike 
off these names if no proper evidence of the occurrence of the 
plants in question in Ohio is forthcoming. 
Yesterday there came to my hands from my friend, Mr. Ros- 
coe J. Webb, of Garrettsville, Portage County, Ohio, specimens 
of three plants which he and Mr. A. D. Robinson, of Ravenna 
had collected in a tamarac bog near Shalersville, Portage County, 
May 24 of this year. The plants were Wolffia Columbiana Karst., 
Ilicioides mucronata (L.) Britt., and Ledum groenlandicumOeder. 
Mr. Webb says the Ledum is abundant at this place and that 
he has known of this locality for about ten years. The specimens 
sent me were in good flower and were evidently taken from 
plants in vigorous condition. This record is noteworthy in that 
Mr. Webb’s station evidently constitutes the only authentic 
occurrence of the plant in Ohio. However, the writer has dis- 
covered a patch of Ledum, about one-half acre altogether, in 
the great Pymatuning Swamp, near Linesville, Pennsvlvania, 
and onlv about six miles from the Pennsylvania-Ohio state line, 
and it would not be surprising if other stations should be found 
for this species in other bogs in northeastern Ohio and north- 
western Pennsylvania. 
Carnegie Museum, Pittsburgh, Pa., May 27, 1909. 
POTATO AGAR. 
Mel. T. Cook. 
The making of potato agar probably presents greater annoy- 
ances than the making of any other medium used in bacterio- 
logical and mycological laboratories. The difficulty is due to 
the starch of the potato becoming gelatinous and difficult to 
filter. For sometime the writer has been using a method which 
has proved very satisfactory. This method is a modification of 
the method in general use and it is probable that other workers 
may be making agar in practically the same manner. However, 
it has been considered advisable to publish it at this time for the 
benefit of any who may be experiencing difficulties in the making 
of this very valuable medium. The method is as follows: 
A. — Melt the desired amount of agar (10, 12, or 15 grams) in 
500 cc. of distilled water. 
