Massachusetts Fern 10 fs 
The delicate pubescence of the leaf-blade and the dark color 
at the petiole’s base are to be seen in the leaf at most if not all 
stages of development. 
The yellowish glands have been found on the leaf-blades of 
all the leaves examined, excepting one or two extremely young 
ones, and offer the simplest means of distinguishing this fern 
from D. noveboracensis and D. thelypteris at any stage of leaf- 
development at which they are likely to be confused. 
It is often said that the venation offers an easy means of 
distinguishing D. simulata from D. thelypteris, and this is true 
of the venation in the mature leaves. In these, the primary 
branches of the midveins of the pinnz’s segments are mostly 
once forked in D. thelypteris and simple in D. simulata, except 
in large, often toothed segments, which are examples of leaf- 
development carried slightly further than usual and in which, 
consequently, they are more complex. But in the early leaves 
of both plants the degree of complexity of any of the venation of 
the pinnz’s segments is changeable, depending upon the segment’s 
state of development, and is not to be relied upon as a distin- 
guishing characteristic until a fairly advanced stage of leaf- 
development is reached. As the venation in both is pinnate, 
the entire venation of the segments is formed by the lengthening 
and branching of the branches of the midveins in the early pin- 
nz, which takes place during the leaf-development. 
