PELLAEA GLABELLA AND ITS SEGREGATES 75 
4. ScHAFFNER, JoHNH. An Undescribed Equisetum 
from Kansas. Ohio Nat. 13: 19-22. 1912. 
5. Busu, BENJAMIN FRANKLIN. Standley’s Ferns of 
Greene Co., Mo. Am.Fern Jour. 6: 112-116. 1916. 
6. FARWELL, OLrveR ATKins. The Genus ae 
aete in North America North of Mexico. Mem. } 
Bot. Gar. 6: 461-472. 1916. 
7. Farwe.i, Ouiver Arkins. Notes on Hippoch- 
aete. Am. Fern Jour. 7: 73-76. 1917. 
Outro State UNIVERSITY. 
TAXONOMIC AND GEOGRAPHIC STUDIES IN 
NORTH AMERICAN FERNS. 
Ill. Pellaea glabella and its Western Segregates. 
FREDERIC K. BUTTERS. 
As stated recently in a note in the Fern Journal,!a 
further study of the western ferns allied to Pellaea 
glabella Mett. ex Kuhn has convinced me that there are 
two species occuring in the western states and Canada, 
closely allied to that well-known northeastern fern, but 
clearly distinguished from it, and from each other by 
numerous characters and by their geographical range. 
One of these, Pellaea pumila Rydb., originally described 
independently by Rydberg from the Black Hills of 
South Dakota,? and by Elias Nelson from Wyoming,’ 
occurs along the eastern ranges of the Rocky Mountains 
from Alberta to Wyoming, the other, my Pellaea 
Suksdorfiana, appears to be confined to the region west 
of Rocky Mountains, occurring chiefly in the inter- 
montane region, and ranging from British Columbia to 
ps Fern vies 11: 39-40. 1921. 
me NY Bot. Grrden, 1: 4. 1900. 
eae Bull.7 2 30: 
