scrotiform spur; and long bracts exceeding the flowers 
—could be referable only to H. viridis var. bracteata. 
Muhlenburg does not mention the lip as having a tubercle 
on its face, a character of H. flava. The spur of H. flava 
and its var. herbiola is never scrotiform, but is cylindrical 
and slender-elongated or somewhat clavellate. 
Specimens in the Muhlenburg Herbarium in the Acad- 
emy of Natural Sciences of Philadelphia afford little sat- 
isfaction toward solving this problem. According to Dr. 
FE. W. Pennell, the folder marked Orchis virescens is in 
the handwriting of Dr. R. EK. Griffith, Curator of the 
collections of the American Philosophical Society about 
1880. Included in this folder are specimens of Haben- 
aria integra (Nutt.) Spreng. and HZ. flava var. herbiola. 
These are doubtless the plants which were merely inter- 
preted by Griffith to be Orchis virescens and, consequent- 
ly, should not be considered as authentic. 
IL. DicHAEA ECHINOCARPA AND ITS ALLIES 
The genus Dichaea is a very natural assemblage of spe- 
cies. However, because of the close affinity of the species, 
several of them are extremely difficult to define. In such 
a genus where various species are almost identical vege- 
tutively, it is essential to make a floral dissection before 
an accurate determination is possible. It is also to be 
expected that natural hybrids will occur because often 
several species may grow matted and entwined on the 
same tree or rock, thus affording easy cross-pollination. 
This creation of a hybrid population adds to the perplex- 
ity of identifying some of the species or so-called species. 
Another disturbing fact is that numerous sterile speci- 
mens have been collected which are, for the most part, 
indeterminable and thus the material with which to work 
is limited. 
The species of Dichaea treated here belong to the sec- 
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