yy, At 
PROCEEDINGS 
OF THE 
WASHINGTON ACADEMY OF SCIENCES 
Voi. XII, No. 3, PP 271-328. FIGS. I-30. AUGUST 15, 1910 
THE POLYTRICHACEZ OF WESTERN NORTH 
AMERICA 
By T. C. FRYE 
University of Washington, Seattle, Washington 
IntTRopucTORY NOTE. 
There is great confusion in the taxonomy of our western mosses on 
account of the duplication of names and the naming of species from 
sterile specimens or single collections. Systematic work on them is 
much needed. To show the way, a single family, the Polytricha- 
cez, was studied from type material and accessible collections. In 
the keys in this paper the characters separating the genera or 
species are given for all, thus making a comparison. So often one 
wants a comparison rather than a description, that it is hoped this 
will prove of value to those using this paper. 
Acknowledgments are due to Mrs. Elizabeth G. Britton for kindly 
permitting the writer to examine type material in the herbarium of 
the New York Botanical Gardens. | 
The illustrations in this paper are mostly from drawings by Elsie 
K. Waddingham. 
POLYTRICHACE. 
Name derived from poly = many, and tricho = hair; referring to 
the hairiness of the calyptra in many genera. 
Plants usually of large size, growing on soil. Stems simple or 
slightly branched, springing from a subterranean shoot. 
Leaves usually narrow. Lamelle present on their inner surface 
and sometimes on the back as well, each usually a few cells high and 
Proc. Wash. Acad. Sci., August, 1910. 
