——— eee, 
HARVARD 
UNIVERSITY 
LIBPARNY 4 
HARVARD UNIVERSITY 
AMBRIDGE, Massacnuusetrs, May 27, 1943 Voi. 11, No. 3 
STUDIES IN HABENARIA AND DICHAEA 
BY 
Oakes AMES AND Donovan S. CorreELL 
I. THe PropuemM or HaBENARIA FLAVA 
HaBeNaria, the largest genus of native orchids in the 
United States and Canada, presents some complex and 
extremely difficult taxonomic and nomenclatorial prob- 
lems. This is especially true of the sections Limnorchis 
and Piperia in the western United States and Canada. 
The most confusing problem in the eastern United States 
and Canada involves the much misunderstood H. flava 
(L.) R. Br. This is due not only to the variability of the 
species itself, and to the inclination of some authors to 
segregate entities based on minor variations, but also to 
the fact that some forms of HZ. flava are superficially sim- 
ilar tosome forms of HZ.viridis (L.) R.Br. var. bracteata 
(Muhl.) Gray. This superficial resemblance is especially 
true of herbarium specimens. 
Although Ames, in 1910, recognized the existence of 
two forms of H. flava, he included them under one con- 
cept. He wrote (Orchidaceae, fase. 4, p. 44): ‘‘ddaben- 
aria flava is represented by two forms, one of which is 
common in the northern United States. That these forms 
are specifically or even varietally distinct from one another 
is very doubtful. The specimens in the Linnaean and 
Gronovian herbaria [Orchis flava] are comparable to the 
specimens with elongated racemes frequently found in 
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