PROCEEDINGS 



OF THE 



WASHINGTON ACADEMY OF SCIENCES 



VOL. XII, No. 3, PP 271-328. FIGS. 1-30. AUGUST 15, 1910 



THE POLYTRICHACE.E OF WESTERN NORTH 



AMERICA 



BY T. C. FRYE 



University of Washington, Seattle, Washington 



INTRODUCTORY 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- 

 ceae, 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^E. 



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. Lamellae 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. 



