142 
Aspidium Boottii, 
THE WOOD FERNS. 
also been described at different times 
as a variety of both species. Present 
day students, however, unite in con- 
sidering it distinct, Nevertheless it is 
a form to puzzle the novice, since it is 
so easily confused with other species 
that it often requires careful study to 
separate them. In the cutting of the 
fronds it is most like spznulosum ; il 
shape it approaches cristatum. 
This species attains a height of from 
two to three feet. The fronds are half 
erect and oblong-lanceolate in outline. 
The blade is about twice pinnate. In 
the lower part, the pinnae are triangular- 
ovate and again pinnate with oblong, 
bluntish divisions, the largest of which 
are cut into blunt segments with bristle- 
like teeth at the apex. In the upper, 
the pinne are lanceolate, broadest at 
base with broad, blunt-toothed seg- 
ments. The frond is always twice pinnate be- 
low, a point that makes its separation from the 
crested fern easy. It is, however, somewhat 
variable in its cutting and some forms are likely 
to be often referred to spznulosum. 
The fertile fronds are much like the sterile 
in shape though usually slightly taller and more 
deeply cut. The sori are rather smaller than 
those of evzstatum and borne in a similar double 
row on the pinnules. Nearly all specimens 
have a tendency to produce one or more sori 
on the teeth of the pinnules as well, thus obscur- 
