716 Aspidium spinilosum and its Varieties. [November, 
medium, and there is seldom any difficulty in distinguishing it at 
all times from all other ferns by which it may be surrounded. Its 
, wide-spread distribution in this country and Europe (where it 
was first discovered and described as a species by Braun, under 
the name of Aspidium remotum, and where it seems to preserve 
its character no less distinctly than with us) entitles it to a higher 
consideration than that of a mere variety, and although its resem- 
blances to cristatum are stronger than its resemblances to spinu- 
Josum, the glandular indusia keep it always distinct from the 
former species. In no instance known to me is there any-record 
of glandular indusia occurring in cristatum- while in Boottii they 
are always present. 
Its anomalous character, however, occupying as it does an 
apparently intermediate position between spinulosum and cris- 
tatum, and the fact that it is generally found growing in company 
with those two species, has led many to regard it as a probable 
hybrid, but a proper consideration of this theory will show that 
while it may be possible for those two species to hybridize as fre- 
quently as this theory would pre-suppose, it is hardly probable 
that they should do so in so many instances, and under such 
widely different circumstances and surroundings without pro- 
ducing some other than this one particular form, everywhere so — 
uniform in its character. But even this theory, if established, 
would only result in raising our plant to the dignity of a species, 
a position to which I think it no less entitled now. 
I retain Tuckerman’s name, as it is the only one by which our 
plant is generally known to American botanists, and having been 
used frequently abroad, it has the additional merit of being the 
best known and most widely used of all names. 
Finally, if it be urged against my paper that, as my investiga- 
tions have apparently been limited to Middlesex County, they can 
only be regarded as partial, I answer that those observations were 
made upon living plants growing in their natural situations, and 
other examinations of a series of herbarium specimens from 
_ Maine, Vermont, Massachusetts, New York and other States, have 
_ only strengthened my convictions in regard to them. 
During a recent visit to Portland, Me., I visited a number of 2 
_rich swamps in the neighboring towns and found A. americanum a 
-tobe the prevailing form in that vicinity. I met with A. spinu- 4 | 
losum but twice, and in both instances the specimens were well — 
marked and characteristic, | 
