32 Lackawanna Institute. 



but interesting species. The work of Mr. Davis has been of 

 great service, and I have often given his name a place on 

 the following pages, because of the indisputable evidence his 

 specimens afforded me. 



Second — Xotes of observations which were generously sent 

 me by Professor Thomas C. Porter, of Lafayette College, 

 Easton, Pa., who is the best authority on the plants of his 

 State. Besides his "Sketch of the Botany of Pennsylvania, ?r 

 published in Gray's Atlas, 1S72, he forwarded selections from 

 lists of plants observed on "The Pocono" and elsewhere in 

 18S1 and 1884, also other notes of much value. In return I 

 hope the botanists of the "Northern Anthracite Coal Valley'' 

 may be able to aid him essentially in the preparation of his 

 forthcoming Flora of Pennsylvania. 



Third— Lists of plants observed by Mrs. Beeber and Mrs. 

 Buell, of Scranton, and Miss Bannister, of the Wyoming 

 Seminary at Kingston, were placed in my hands, although 

 they had no collections of pressed plants. 



Fourth— The present Director of the Arkansas Geological 

 Survey, Professor John C. Branner, who is the authority 

 on the topography of these valleys, gave me many valuable 

 hints as to interesting localities, and accompanied me on sev- 

 eral excursions. 



Fifth— I have had my own collections and observations 

 made during a week's stay in Scranton and on the Pocono in 

 June, 1886 ; also in the exploration in the Wyoming Valley in 

 the autumn. Quite full notes were taken down at the time, 

 and the more interesting plants preserved in my herbarium- 



The plan of the catalogue is as follows :— (1) All references 

 to localities are for the Lackawanna and Wyoming Valleys 

 and the mountains immediately bounding them. Because of 

 their interest and proximity those plants we know to occur 

 on the Elk Mountain (the highest point in X. E. Pennsyl- 

 vania), and those at Tobyhanna, Gouldsboro, Lehigh Pond 

 (near Gouldsboro and the source of one branch of the Lehigh 

 River), Moosic Lake and other places on the neighboring 

 Pocono plateau are included. "Common" means common 

 over the areas of the valleys. (2) If a species is apparently 



