P R E F A C E .
F e r n -lo v e r s in North America have often expressed a wish for
some work devoted to the illustration and description of the Ferns of
the United States and the British Possessions. To meet this wish is
the design of the present undertaking.
The sixty years which have elapsed since the publication of Nut-
tall’s Genera o f North American Plants have seen the number of recognized
North American Ferns more than doubled. This great increase
is due to a more general botanical interest in the older parts of the
land almost as much as to discoveries in, newly acquired territory. Nut-
tall gave the names of only seventy Ferns: in 1848, Kunze reviewed the
list, adding about ten species to it, and rejecting several names as not
representing distinct species, or as not belonging to any North American
plant. About the same time the acquisition of New Mexico, Arizona
and California, and the various governmental explorations of these regions,
brought to our Flora about twenty-eight more P'erns, many of