Rbodora 
JOURNAL OF 
THE NEW ENGLAND BOTANICAL CLUB 
Vol. 21. October, 1919. No. 250. 
CHANGES IN THE NOMENCLATURE OF THE GRAY’S 
MANUAL FERNS. 
C. A. WEATHERBY. 
In the course of preparing, as their second report, a preliminary 
list of the New England Polypodiaceae, Schizaeaceae, and Osmundaceae, 
the Committee on Floral Areas of the New England Botanical Club 
has been confronted with certain questions of taxonomy and nomen- 
clature. Asa result, the names used in their list will differ consider- 
ably from those in the 7th edition of Gray’s Manual. The following 
has been written by way of explanation of these changes and in the 
hope that it may be of some service to users of the Manual to have the 
matter relating to them brought together in one place. 
There is probably no other family of plants in which the accepted 
basis of classification has been so radically changed within the past 
few years as in the Polypodiaceae. The ferns, though an ancient group, 
have proved exceptionally conservative; their evolutionary variation 
has been confined within narrow limits and they present today a com- 
plex of closely inter-related groups, merging more or less into one 
another. They offer, therefore, especial difficulties in classification. 
All of the very different systems proposed by the older writers have 
been artificial to a greater or less degree and have suffered from laying 
too much emphasis on single characters or single kinds of characters. 
It is only within about twenty years that Diels has devised a system 
based on combinations of characters — a system which, so far as our 
present knowledge shows, seems essentially natural and which has 
gradually won its way to practically unanimous acceptance. It is 
because of these conditions in general and, in particular, of a consider- 
