Rhodora 
JOURNAL OF 
THE NEW ENGLAND BOTANICAL CLUB 
Vol. 19. December, 1917. No. 228. 
A REMARKABLE COLONY OF BIDENS IN CONNECTICUT. 
M. L. FERNALD. 
In September, 1910, Messrs. R. W. Woodward and C. H. Bissell 
collected on the strand of Lake Pocotopaug at Chatham, Connecti- 
cut, material of an abundant Bidens which was afterwards, in 1915, 
referred to the writer for his opinion. The plants were of two quite 
definite strains and superficially somewhat resembled B. connata 
Muhl., var. petiolata (Nutt.) Farwell in its most extreme development, 
the oblong to lance-ovate leaves being all on very slender elongate 
petioles. Unlike any form of B. connata, however, all the material 
from Pocotopaug Lake was consistent in having the achenes quite flat 
and always two-awned, exactly matching the achenes of B. hetero- 
doxa (Fernald) Fernald & St. John,! a species hitherto known only 
from maritime habitats on Prince Edward Island and the Magdalen 
Islands. 
As above stated, there were two distinct strains of the plant from 
Pocotopaug Lake, the larger plants having the two awns of the achene 
consistently retrorse-barbed, as in most species of Bidens, and in 
this exactly matching the achenes of Bidens heterodoxa, var. ortho- 
doxa; the smaller plant of the strand (mostly much smaller than 
the plant with retrorsely-barbed awns) having the awns quite smooth 
and barbless or at most with very obscure suggestions of barbs, 
appearing as a slight scabrous tendency on the awns. These plants, 
presenting, as they did, the achene-characters of B. heterodoxa, a 
species known only from subsaline situations about the Gulf of St. 
1 Fernald & St. John, Ruopora, xvii. 23 (1915). 
