Ilovember 13, 1910 
Mrs. Ella L. Horr, 
Worcester natural History Society, 
Worcester, Hass. 
My dear Mrs. Tlorr:- 
I don’t know as I should like to be quoted as 
saying that every Polytrichum of the ’’commune” group under 
6 inches in height was not P. commune , but there seems to some 
ground for such a general statement provided it is coupled 
with other important characteristics. 
Since the publication of my ”Preliminary Lists of Hew 
England Plants—XIX” in Ehodora, Vol. 8 (1906}--a reprint of 
which I sent you some time ago—-my studies on Polytrichum have 
only strengthened and reinforced the statements made there in 
regard to . conmune and peri g on lale . 
I feel almost prepared to say definitely that our most common 
-olytrichum is P. poriponiale , and that the tru European oonnunc 
is even rarer than I supposed at the time the article mentioned 
was written. 
Very truly yours. 
