Preface to the First Edition* 



The aim in the preparation of this Manual has been to make it a practical 

 handbook applying particularly to the region of western Pennsylvania and 

 embodying all that is at present known regarding the occurrence and distribu- 

 tion of mosses within that area. As a matter of fact, the Manual will be found 

 to apply also to the adjacent regions of central Pennsylvania, extreme south- 

 western New York, eastern Ohio, and northern West Virginia. 



When the present writer took charge of the botanical collections in the 

 Carnegie Museum in 1904 he found that the Herbarium, aside from certain 

 specimens collected by Mr. D. A. Burnett in McKean County, a iew years 

 previously, contained but little to represent the rich flora of messes and liver- 

 worts to be expec.ed in the western end of Pennsylvania. One of the aims of 

 the Herbarium of the Carnegie Museum has been to assemble a very complete 

 and comprehensive collection of all the plants to be found in the general region 

 in which Pittsbur[;h is situated, and, in the prosecution of this v/ork, the 

 writer has been enabled to visit all of the counties in the \7estern half of 

 Pennsylvania and also adjacent portions of Ohio and \7est Virginia. Certain 

 localities in this general region have been made the subject of detailed ecologic 

 and systematc study and collection — particularly the peninsula of Presque 

 Isle, near Erie, Pennsylvania; the extensive Pymatuning Swamp in Crawford 

 County, Pennsylvania; the mountainous region in the vicinity of Ohio Pyle, 

 Fayette County; and the larger portion of Allegheny County, especially in the 

 vicinity of Pittsburgh. From these and other localities visited, extensive col- 

 lections of r-.osses have been made and the amount and representative nature 

 of the herbarium material thus available for study have becom.e such that it 

 has been deemed advisable to prepare a treatise embodying the results of the 

 work accomplished, thus placing within the reach of other students of the 

 mosses v/ithin the region a convenient m.eans of identifying and checkinrr their 

 collections. It is hoped that with all its faults this Manual may be to some 

 extent the m.eans of stimulating bryological study in a region of v.'hcse mosses 

 there is yet much to be learned. 



In the preparation of this Manual the author has taken as the taxonomic 

 standard the monumental work of Warnstorf, Ruhland, and Brotherus, brought 

 to completion in 1909, in Engler iC Prantl's Die Natiirlichen Pjlanzenfa-milien, 

 Teil I, Abteilung III. In the characterization of the various orders, families, and 

 genera, these authors have been followed closely, and, while there is much to 

 be said against their arrangement of families in certain cases, it is nevertheless 

 very probable that their work will remain for a long time the standard and 

 that, from the standpoint of convenience at least, a similar sequence of families 

 in this Manual is justified. In the determination of the various species the 



* This wor!- in a more condensed form was submitted as a major thesis in candidacy 

 for the degree of Doctor of Philosophy in the University of Pittsburgh, June, 1911. 



